We bought a new 23LB in 2013 and haven't had any serious or big issues with it yet. I did have a wheel well liner that wasn't attached correctly from the factory. It wasn't a big deal and I repaired it myself with some calking and a few stainless screws and washers. I also made a by-pass on the water filter after reading all the comments of them leaking or breaking. Other than that, there were just a few small, common problems found on most RV's today.
One thing to look for on your inspection is for any screw points from the flooring (or frame) that may be in the tire areas. I found one on mine that protruded about an inch into the wheel well area and was very close to the tire itself.
But for the most part, we've been very happy with our 23LB. The Murphy bed option along with the bunks are two factors that helped seal the deal for us. I also purchased an Equal-i-zer, 1,000/10,000, 4 point weight distribution hitch (from Dyer's RV - best price I found) and now the 23LB tows with zero sway like it's not even behind my F-150.