First of all, the 394 is the only 3 series saw that didn't get the side tensioner upgrade, and the 395 is the same. While some guys don't mind a front tensioner, I see no reason to own a saw with a front tensioner if I don't have to, although I do have a great running 242xp with mild port work done and the squish set. The 394 is a tough saw, just not one I need or really want, I'd buy a 661 or a 660 if I needed a 90.
Most everything that needed to be said about the late 550mk1 has been said here, summary; the issues of the early 550mk1 had been fixed, best handling 50cc saw and best for ergonomics(some guys prefer stihls), and they are lighter than the new 550mk2.
You already have the 346, the 50/70 equivalent would be the 372, I like a nice 50/70 saw plan as I don't run the 60cc saws as much if there's bigger wood to be cut as the weight difference with some of the newer and even older 70cc saws isn't that much for the power difference.
Yes original vs the xtorq. While both saws run well, the original was what went with the 346, the xtorq came when the 550 was out. As stated above I was just giving you a hard time about needing the ported 372oe since it was the corresponding saw to the 346, but a ported 500i is a nice saw too(but prefer the handling/ ergonomics of a husky).
Pros cons of the oe vs the xtorq, oe is lighter, xtorq has a wider sweet spot(power band) and gets better fuel economy. Xtorq is heavier and has plastic cages in the bearings that can melt/have issues, and it also has a limited coil that makes tuning more difficult for many. The handlebar on the oe is smaller(in diameter) which some guys like and others like the larger one. The handlebar on the xtorq is also taller so the xtorq doesn't handle quite as nice as the oe.
Almost forgot; why I bought all the 346 chassis saws, I like saws, and the 346 is one of my favorites, I've also bought/sold many saws, more so in the past. You can build a 346 on any of those.
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