Setting aside questions of economics or whether or not fellow BPLers have been on "real backpacking trips"...
If you have experience with Mystery Ranch packs, please share it. I'm not sure if you do, since you ask "Anybody used one of these packs...?" but also mention their "outstanding suspension systems" 4 times... I'm not sure if this is sales pitch or honest inquiry.
Anyway, assuming the best, this is my take: I have little doubt that the MR packs are well-made, just like DD models. I have little doubt that they carry well. But they are indeed heavy and seem like they're a bit more targeted towards expedition/climbing use, and lack some of the niceties of more trail-oriented packs. The SnapDragon has a somewhat smallish 3-season volume of 2700ci... but it's nearly 4lbs. The 2200ci Daily pack is more than 3lbs. Bumping up the volume, we see the packs in the 3000-4000ci range are all more than $200 and 4lbs. For bigger loads in harsh environments, they might be a good bet--but I'm not sure what particular use you had in mind or what pack weight and terrain you normally deal with.
Of course, comparing entire product lines is a fuzzy sort of science. But considering the average lightweight or ultralighthiker in typical US mountain conditions, and considering the expense & weight of competitive products... I think a better option would be something from ULA, Granite Gear, GoLite, Six Moon Designs or similar manufacturers. You can find some excellent, long-lasting packs with comparable load-carrying abilities for half the weight and for significantly less money.