In a similar mind set a few years back, I built myself a 372 (Original "non" xt) based saw with 365 top plastic and filter. Put an eighteen inch Sugihara bar & Oregon LGX...great saw. It was both lighter and easier to deal with than the high top version. Certainly lighter and more compact than a high top 372xt with a 24 inch bar! The new XT versions have packed on a bit of size & weight as compared to the original ones. Since then I took a "damn the torpedo's" approach and built myself a 562 with a 20 inch Total lite bar. Its a match of a stock 372 from a power perspective and a WHOLE lot lighter, less vibration too. I haven't had any of the much talked about issues. Maybe because my tweaks were about ridding heat from the system or maybe I just have the statistically good bits and pieces, really couldn't say. (It started as a toasted 2012 version, got a new set of "six screw" cases, an el48, & my tweaks which include a popup, cut cylinder base & flange, muffler mod, cover mods) It was hot as hell this summer. No issues of any kind yet.
That Dolmar (Now Makita) looks interesting and seems to be a legitimate option in my mind...especially if you have a dealer like the "Cutting Edge" around. The Echo I see a lot, hear a lot of chatter about on line....but have never ever seen one in the field so have no opinion. I personally rather see in real life than read about when it comes to mechanical things. I have seen the Dolmars.
I've seen the Stihl's as well....