^^^^ c'mon. Compare apples to apples.
If you're gonna suggest the SP Maestro, you're working up the ladder on buying more machine for more money. If you're gonna compare the Alpha Revo 4000 and Gamma Progression STII to something Silent Partner, you gotta compare them to the Crump.
If you start looking for upright machines with more options Alpha, Gamma, and Silent Partner have several offerings.
I see the opposite, an advantage of having a table-top machine is the portability. If the OP has limited space, or doesn't want to have a stringing machine taking up floor space, he can more easily put it away. As for more mobility, it's nothing a wheeled cart can't fix.
I've seen many an example of people that use wheeled utility carts as stands for their machines. Lots of great pics here on TTW. Plus those setups have tons more at hand storage for stuff than the pole stands of your typical upright.
As for an Eagnas Comet - from what I gather, their retail paradigm is one you have to step into with some trepidation. Low prices plus poor customer service post purchase......hmmm.
Personally if I were buying a machine, I would want to know as much about user experiences as possible. I started with a table top, soon found it awkward to lug around, and so put it on a table. It sat there for a couple of years, and I strung around the table. Pain in the butt. Next I upgraded to a crank machine on a stand, and have to say, once you get that setup, you will dump the table. It is engineered for stringing, and for me a big plus.
For as the two machines selected, I don’t have a preference, but what I do is have a warning on purchasing 6 knob systems. If you do any volume at all, you will discover, setup is a pain and time consuming. The new systems, like the Comet, Alpha Apex, and Gamma 2 point are much easier and faster. The 6004 2 point is the best, and easiest I have used.
For as Eagnas machines, my 3 1/2 year old Flash 925 ($450 off big auction site), with crappy 6 knob mounting, and cone lock clamps continues to work flawlessly. I have no issues, but in the $700 price range, I would expect a stand and a better mounting system. The SP Maestro has excellent clamps (better than Eagnas, Alpha, and Gamma), decent mounting, and it is a nice machine to string on.
It is a shame there is no place to try machines before you buy. I learned a lot from traveling to different pro shops and using different machines. Prince Neos and Gamma 6004 2 point is still at the top of my list, with the Maestro second, and the Comet third.
Any machine is better than no machine!