My experience is somewhat similar, the drivetrain is dicey but then again, I've read bad things about GM engines and transmissions lately as well. In fact, a bad GM engine design I owned led me to Ram after a buddy bought a Ram. Then the test ride and interior of Ram sold me.
I think I'd buy the Ram again since the transmission was upgraded (but a complete PITA to change oil on), and baby the Hemi rather than have another GM with failing engines and transmissions with crude interior and ride?
I'm on the GM forums (daily) for a number of years, GM's 5.3 and 6.2 have a very bad batch of lifters between a certain set of dates, far more so than normal. But yeah their AFM/DFM system doesn't seem to have a great reputation, so I'd never trade my hemi for a 5.3 or 6.2
I'm also not a fan or turbos. But as a base engine, GM's 2.7 is far better than the pentastar and Ford NA v6; more power, better MPG. I was shocked at how good it felt when I test drove one, it had loud AT tires on so I couldn't hear the engine at all and I was constantly thinking "this has got to be the 5.3" but when stopped and listening to it idle, no doubt it was the 4 banger. So I'd have a hard time paying for the 2.7 as an upgrade, but as a base engine in an entry level trim...?
It is also tuned really well, the transmission is very quick to both downshift and upshift which means you get your power instantly and the RPMs are where they need to be to spin the turbo but it upshifts as soon as you get off the gas. Makes the ride a little more "busy" than in my truck which is more relaxed and smooth which may upset me more if I drove it longer than 10/15 minutes, hard to say.
So IF: big if, I went to GM, it would be either the 3.0 diesel or the 2.7. I'm not going to jump from the hot pan (hemi) into the fire (5.3/6.2) as that's pretty pointless and gets me knowhere; it's a side move that doesn't get me any better MPG, nor is there any guaranteed I get a more durable engine, and I get a worse transmission and ride and interior.