@Stonefield - Some answers to unaddressed questions:
Re- Multifeel durability, it is slightly more durability than most multis because it has a solid monofilament core (like syn gut), so it tends to hang on by that single filament after most of the microfilaments have shredded away, and tends to not snap as soon as pure multifilaments like X-1 or Velocity, which, at the same gauge and level of wear stress, will often snap first. However much that difference is depends of course on a whole host of other variables.
Re- RPM Soft versus Triax (or RPX), they actually are
not that similar at all.
RPM Soft (formerly Origin) is a polyamide (fancy word for nylon) monofilament, with absolutely ZERO POLY in it. It plays very similarly to a soft but lower-powered syn gut, and holds tension just about as well. It has two additional layers over the nylon core: a aramid/nylon middle layer for durability and a silicone/nylon outer layer for slickness/snapback. Diadem Evolution is very similar in its composition. Here's a graphic of the construction:
Triax and RPX on the other hand, are made up of roughly 50% nylon / 50% poly fibers, suspended in a polyurethane monofilament, and are noticeably more crisp (especially RPX) and controlled/lower-powered, but also exhibit a fair bit more initial tension loss and also experience progressive plasticization (ie. "poly death") throughout their life. Here are the graphics on Triax and RPX (notice, Triax has "thermo", or heat-treated, "improved" poly fibers, but in terms of playability, they're very close, and I actually prefer RPX, as it plays firmer, but that's neither here nor there...):
Both are excellent strings, when used in the right application. For Triax/RPX, IMHO (and in
@g4driver's as well), I think it's best used as mains in a hybrid with soft, very slippery poly crosses -- either IsoSpeed Cream or Gosen G-Tour 3 (you might add Poly Tour Air, but I avoid it due to sub-par tension maintenance compared to Cream and GT3). For RPM Soft, it and (and Diadem Evolution) is best used as a cross to poly mains, to soften the string bed while providing snapback and durability.
Hope all of that helps!