While I wouldn't say ignore the negative things you've heard I would say take them with a grain of salt. A lot of people find forums because they are looking for a solution to a problem so what you see on the forums is usually skewed heavily toward people having issues.
Beyond that I've found a lot of the issues could have been avoided had the dealer done a proper job of prepping the RV and/or the customer had done a proper job of doing a pre-purchase inspection.
I would go back to the unit you both liked and go over it with a fine tooth comb running EVERY system, turning EVERY knob, opening EVERY door, flipping EVERY switch, looking in EVERY cabinet and storage space, etc., etc. Don't let the dealer just tell you how things work, have them show you that they work including running hot water, heating water in the microwave, sticking a DVD into the DVD player and seeing/hearing that all the speakers work, checking the frig temperatures and A/C outlets with a laser thermometer, plug in a outlet tester into every electrical outlet, look at all the walls, ceiling and floor with a flashlight from different angles, do the same regarding the outside walls, under and on top of the RV with the slides in and out.
Then, if you find issues see what kind of cooperation you get from the dealer regarding taking care of them (of course before you sign any paperwork or make a payment).
I think you get my point. I have found that a significant number of the problems posted on forums are issues that were first discovered during the maiden voyage with the camper and could have been avoided had the dealer done their job correctly. Doing a thorough pre-purchase inspection says nothing about long term reliability of the camper but you at least want the confidence that when you left the dealer's lot everything was in working order.
Beyond that the issue of long term reliability is very much associated with how the trailer is going to be used. As someone else mentioned, reliability concerns are going to be much more an issue depending on the amount of abuse the trailer has to endure. The abuse is going to be much different for a weekend warrior versus someone that is a full timer driving towing 12K miles per year.