I've owned and tried a lot of different Wals over the years and found that, like most basses, they vary a lot in tone and playability, so you have to try a few before you find 'the one' that suits you best as a player.
My personal favourites are the early Pro models which have an ash body, don't have the 'filter' e.q. and are more gutsy sounding than the Custom models in my opinion.. They also have the big headstock (which I love) and weigh a ton and have bad neck dive.. But it doesn't matter to me because I just love the tone/look of them.
Isn't it great though that there are so many fantastic basses to choose from these days; whether you like Wals, GBs, Sei's, Overwater, Status, Shuker etc, etc, the custom bass market in the UK just has so much to offer it's brilliant!