First of all, I want to thank TW and Tecnifibre for allowing me to playtest these strings, especially in a Steam 99S. As a Steam 99S user, I didn't expect the typical type of play I get from the co-polys I use or the Natural Gut/ co-polys.
What I did get was in fact very promising.
Tennis experience/background: Picked up tennis in high school after playing baseball for a long time. Played recreationally during college as a 20 year old and after college, then came back to the game in 2006 after a 10 year break.
Describe your playing style (i.e. serve & volley): USTA Rated 4.0 player who plays singles and doubles in almost equal amounts. In singles, I tend to stay mostly on the baseline (about 90% of the time), in doubles I am coming in about 90% of the time. I mostly play singles against guys 15-20 years younger than me, as 90% of the guys my age only play doubles.
Current racquet/string: Steam 99S with Volkl V-Torque 16G / Head Hawk 16G
Tension used for playtest 58/56 strung on a Prince 6000.
Regular string set up Volkl V-Torque 16G / Head Hawk 17G
Racquet brand and model used for test Steam 99S - modified.
I am going to do something TW didn't ask for. I hope others find the star rating system useful. Up to 5 Stars available in six categories. I am going to skip "Power" since that is a personal preference.
Power of test string Very Powerful. I expected this and strung it pretty tight. I think I would go higher if using as a full bed for me in a 16x19 frame. This string really didn't work in my Steam 99S after five sets of doubles. (more on that later). Unrated for Stars. Power is a personally preference. Some want more power, while others want dead strings that you have to supply your own power, hence no rating for the Power.
Feel (Stiff? Mushy? Muted? Crisp?) 5 Stars - This string felt wonderful IMO. It is softer than polys, and it felt like a nice natural gut when hitting. I have had TE issues in the past, and hit with full poly in a Steam 99S frame measuring 70 on a Babolat RDC. This string was very nice on my arm.
Spin 2 Stars probably average compared to pure multifilament. I don't hit full beds of multi, so this is hard for me to give a comparison. But producing a lot of spin isn't going to be a major plus for this string.
Comfort 5 Stars As comfortable as X-One or NRG2. More comfortable than Duramix, which I don't care for. I think this string feels softer than NXT Control, but it has been a few years since I hit with NXT Control.
Durability 5 Stars More durable the 16G X-One Bi-Phase and NRG2. (5 Stars for a multifilament) X1, NRG2 and other multis would be severely fraying at the same amount of playing time as a full bed of multi. I broke the last two sets of V-Torque mains before completing six sets on each frame, so this string as outlasted my last two sets of poly in my Steam 99S. Very impressive.
Playability Duration (thoughts on if/how the playability changed over time)
4 Stars At first, this string was snapping back nicely in my Steam 99S, and I was hopeful this would continue for 12-14 sets. Unfortunately, after three sets of 8.0 mixed doubles, three sets of 4.0 Men's doubles, a 90 minute drill with 4.0 and 4.5 guys, and a two games of singles with a 3.5, the mains stopped snapping back. I noticed some notching after the third set of 4.0 doubles. The strings are slightly frayed, but they aren't close to breaking. So for durability, I think I could easily get better mileage from these strings than X-One and NRG2. 2 Stars if I was only rating for the string in a Steam 99S. I expect it will do much much better (expect 4+ stars) in a smooth co-poly/Tecnifibre ATP Multi 16g hybrid.
Control: 3.5 Stars Control started to be a factor when I started playing singles vs the 3.5 and the mains had already stopped snapping back. Tonight in the first set of singles, I went down 0-2 to a player who has beaten me once in maybe 30+ attempts of singles. I kept hitting short balls in the net, or long unable to generate the topspin and control, I have grown use to with my Steam 99S V-Torque/Hawk frames. After going down 0-2 after missing a short ball that should have been an easy winner, I put down the frame with the Tecnifibre full bed of this test string in it. I knew the strings were no longer capable of doing what I wanted with them.

This is merely a bad marriage of this string to my Steam 99S. I expect the control to be very nice in a 16x19/20 or 18x20 pattern, hence 3.5 Stars.
After grabbing another Steam 99S with V-Torque/Head Hawk, I won nine straight games going up 6-2, 3-0 before finished the 2nd set for a 2&2 win. My buddy commented how I changed after losing the first two games. I told him I had to change frames. This wasn't a knock on the Tecnifibre strings so much as I am use to V-Torque/Hawk or a full bed of Cyclone Tour, and I was playing with a Steam 99S, which isn't really designed for multi strings. These Tecnifibre strings were moving all over the place and it was annoying to be adjusting strings after every point. It was more troubling to miss long or in the net, time and time again. The fact I got this far with the Tecnifibre string is impressive to me considering the frame I was using.
Compare to the string you use most often: Comparing to full polys in the Steam 99S. Tecnifibre Multi ATP 16g: Less spin, flatter shots, less control the more I played with the string, more comfortable and more power.
Tension recommendations: higher for more control. lower for more spin.
Will I use this string in a Steam 99S? No. But I will never use any mulit in a Steam 99S, so this isn't a lost cause.
Will I recommend this string to anyone who likes copoly / multi hybrids ? Yes, I will and strongly recommend this string in the crosses with a co-poly mains, and even as mains with a smooth co-poly cross, because I know some folks who like the multi mains. This string should last much longer than the average mulit IMO.
Do I think this string is vastly super to Duramix? Yes, without a doubt. It feels more comfortable than NXT Control which I play tested, although in a Wilson Pro Open 16x19 frame.
We are including Tecnifibre Pro Contact Overgrip with the playtest string. I should have saved this for the fall. Too humid to use in the southeast with all the humidity. Wilson Pro Overgrip or Tournagrip - are the only two that work May - Sept for me. But I did like the feel.
P.S. When I get a chance I plan to cut of the mains of this string and see how it works as a cross with Black5Edge in a Pro Open trying to do a direct comparison to X-One Bi-Phase, unless Tecnifibre sends me another pack.
Overall 24.5 / 30 Stars for this new Tecnifibre String or 4.1/5 Stars. Nice String by Technibre and yes, I would buy it and use it as cross for friends/customers who use hybrids. Especially to string breakers who don't like full poly.