I imagine most pilots hired at a regional in the last few years probably can't accurately compare... But ask anyone who was hired by an airline around 9/11 and they can probably give you some good comparisons (because they've been unlucky enough to train at more than a few airlines)... For me, I've been through 5 major training cycles at 3 airlines in 7 years...
I've gone through 3 major training cycles at XJT: Initial & Upgrade ERJ training were both fantastic. It is done completely in-house and they truly have ERJ training down to a science. They have 3 of their own Sims, and they download actual aircraft data into them to make them fly more realistically. They put you in a cabin trainer filled with smoke and you are part of a simulated aircraft evacuation being led by a Flight Attendant trainer, which is a huge eye-opener. CRM training is thorough and relevant. The Instructors are organized, knowledgeable and helpful. All in all, an excellent training program. (But God help you if they are slammed with new hires and you get put down at the Flight Safety Sims at Hobby and get "Number 2"... For a full year, I believed the actual aircraft would roll inverted if you lost an engine on takeoff...

)
The other was pre-9/11 - Initial ATR, which XJT no longer has - but the Sims were completely outsourced to Flight Safety and I found that to be barely adequate and disjointed because their Instructors weren't intimately familiar with XJT procedures. (I've heard similar complaints from CHQ crews, whose entire training course is outsourced to FSI.)
I went through Initial B1900 training at CommutAir and found it to be adequate. The instructors were knowledgeable and friendly, but I found it to be not as thorough as I would have preferred.
I'm currently in DAL MD-88 Initial and so far it's been excellent. They also put you in a smoke filled cabin trainer evac with a F/A trainer. Most of your instruction is done 2 on 1 (2 students with 1 Instructor). I'd say the only thing I've noticed so far is that they give you a lot of books and paperwork to study (which is done at home) with not enough guidance on what to concentrate on.
Hopefully some more unfortunate souls who have been through more than one airline in the last few years will also chime in.