The only payware I have is GA aircraft, but any of the planes by Carenado are great, I dont have the Mentor though, but everyone says it is a good one 
I have the FSD Piper Seneca V, it is a great aircraft, and I have the Dreamfleet/Flight 1 Cessna 310, and Piper Archer both of which I like very much, although the 310 seems a bit hard to land....

I also have the Eaglesoft Beechjet 400A/Premier 1 package. I like both of those except for the fact that the panels are kinda hard to read, the Beechjet panel is a bit better than the Premier 1 though.

Anyway those are what I have, and my feeling on them, so good luck with whatever you choose 

while the CRJ is a nice addon, it's far from a complex one, I wished I saw this thread earlier, then I'd recommend the ERJ-145 (developed by the CRJ team, Feelthere), the PMDG 737 or the upcoming 767 from Level-D Simulations.
Those  blows the CRJ away...nothing against the CRJ (I have it myself), but as the founder of Feelthere said in their forum

"The CRJ is a little bit simplified plane we were looking for some sort of ballance between complexity and easiness. On the ERJ the goal was to create the most realistic regional jet for FS.
If you like to fly a realistic plane I would go with the ERJ"

Took me some 40mins before I mastered the CRJ, so it's not that complex. What I truly lack is a complete FMS. Since the navdata is far from complete, it would be nice to at least create custom made waypoints like P/B-P/B, P/B/D, Lat/lon etc, but that's not possible with the CRJ.

I just checked over at flight1 and the Meridian does include the full RXP Garmin and Meggit gauges.  That suprises me because many of us have panel editors or are otherwise sharp enough to borrow gauges from any panel and use them in any other panel.  Unless of course RXP has the Meridian installation coded so it will only play with the Meridian panel which I know is done with most  commercial add-on FMC replications.  I know, I've tried to de-compile and re-use more than a few and havn't gotten any to work yet.  Turns out that the CRJ is on back order from flightsimcentral, not expected til the first of the year so I substituted the 737 NG instead. Same price.  I just wanted something that would fit on shorter flight plans and smaller runways because I rarely have enough time to do 2-4 hour flights and I don't like the performance decrease that big airports cause.  I was going to substitute the Dash 8 professional but I noticed they had 2004 compatibility as limited so that scared me off. I haven't gotten my confirmation email yet so I don't know if 737 NG is on back order or not also.