I have had both an L 2500 and an M 2500. I got the M 2500 in a trade and was surprised at how much I like it. It is easier to tweak the tone on the M but the L can get close once you learn to use the preamp. I preferred the passive tone of the L when I had it.
By a small margin, I prefer the M. Both are killer and you shouldn’t be disappointed with either. G&L basses are lovely.
By a small margin, I prefer the M. Both are killer and you shouldn’t be disappointed with either. G&L basses are lovely.