The most annoying, I find, is that there's so little practical provision for PSU bypass on the adapter itself. The result is extremely long paths from supply connections to bypass members. I've tried soldering them and adding wires to make the supply runs shorter, but it's a crapshoot. Sometimes it does little good.

Those 0.100" (2.54 mm) matrix adapters to which one solders a PLCC or TQFP, etc, are a tradeoff, particularly as one hopes to get better performance, since the leads tend to approach 6-8 cm by the time they're connected to the "outside world". I use 'em, but they're a mixed blessing.

RE