Make sure they have gold plated connectors. I think the Hobico ones do. I don't buy non-gold plated anymore, and will sometimes snip the leads off of servos that aren't gold and solder on new ones. Connector corosion sucks.

(btw, connectors that you unplug and plug often, such as removing a wing, generally won't have corrosion problems, but the ones you leave plugged in all the time can sometimes get flaky after a while, gold plating reduces this problem quite a bit. (I'd say "eliminates", but I hesitate to imply 100%)).