Snap-in caps work fine- as well as any other electrolytic.
Most electrolytics will have similar performance. Its mostly about the application- for example some situations they might need to handle more ripple current, or survive higher temperatures. Take a look at the part you have in there right now. If it is rated for 85 degrees C, then that is the less expensive rating- the higher rating is 105 degrees C. Performance-wise though they are the same.
Just make sure your replacement part has the same voltage rating! Personally I go with recognized brands whenever I can: Nichicon, Sprague, Illinois, Mallory, that sort of thing. Don't buy electrolytics off of ebay- there are Chinese counterfeits out there that will blow up quite readily.
Newer caps tend to be smaller than older ones. Its been that way for decades. So don't worry if the replacements are a little shorter- that's a good thing. It means your replacements are new :)
