I have an '87 Warwick Streamer neckthrough which is definitely one of my favourites and would not think of selling it - very slim neck, light cherry body wings, PJ pups - great on a 2 hour gig. However, I had a Streamer Jazzman 4 for a few years and while very versatile, I found it to be a bit compressed in the lows and had too chunky a neck for me, so traded it on. I am a great Fender fan also, specifically P basses. From personal experience, I have made the mistake of buying a bass and expecting it to sound like a Fender. Warwicks are different in a great way IMHO and now I just enjoy the difference and use each bass for the occasion that most suits it.
Great advice above - Go and try them. Like Fenders, some appeal and some don't. Althought the Stage II is arguably the cream of the crop.
Good luck in the search!