I have a Pro IIe and some customs. Other then the obvious diference of controls and such, The electronics in the old Pro models are very different to the Custom models.. though having said that, Wal basses do have a 'sound' that is quite distictive and IMO, can be heard in both the Pro Models and the Customs. However, the Custom models have a much more versatile e.q. system..
picture a Mk I with a bit less of a glassy top-end, and perhaps a tiny bit more low-end... Love em both though !!
Sadowsky#417|Wal Bass#35|MesaBoogie 400,400+#50|Fretless#821