I've own 3 bass so far, Fender jazz, warwick vette and G&L Trib L2500. Always wanted to trade out the G&L for a Fender Highway P or Musicman sub. Went to the shop today and try out the Fender Highway and i ended up not buying or part ex the Tribute for the fender because i feel my G&L is much more better in term of sound. So walk out the shop with nothing today. I always feel i don't need to get rid of any of my bass for something else, since the 3 bass i have at the moment cover alot of sound already. I just need to stop thinking about buying new bass because i don't really need it. I think i will put the money on putting a J-Retro preamp on the jazz and upgrade the G&L preamp for even better tone.
I have one bass. This site gives me gas once in a while so I take a trip to my local Store and try them. So far GAS goes away because the bass guitars I would consider all cost too much money and I really don't need them. Buying stuff off EBay is like waking up with an ugly woman, either you can't take it back or its not expensive so you just put up with it and pretend its something good because it was cheap.
Yes, the Analogy was horrible I keep seeing reviews for bass guitars (get gass) and then try them at the local store and I'm usually disappointed and glad I didn't have something shipped with out trying it first...like the Squire modified precision.
I think it depends on how long you've been playing, the set up of the bass, the rig you're hooked up too etc. I played a warwick thumb once when i had only been playing for 2 months and I figured my Stagg P bass clone was better! ROFL. I guess like all things it take time to develop a taste. That said however you're right it's always best to try before you buy.
I theory on it is if you can't take care of what you already have (maintenance, gig ready condition all the time) then you shouldn't buy more. But that's just me....