That's most helpful, thanks - it still leaves me undecided though

Seems like the 4 is a travel limited 5 then, with no weight saving - can see now why there's so many 5's around and hardly any 4's (though it is pretty hard to spot the difference)
Other way to think of it is they're both cracking bikes, one a little less travel but with better finishing kit for the same price.....
..will I notice the missing 32mm more than the better componenets, probably not, especially on the local trails (Hurtwood/Swinley/Tunnel Hill) - don't plan to start being a DH type so I'm thinking components over travel (for today anyhow!!)
Bugger!! by the time I've faffed around trying to decide they'll be sold out of '08 models anyway

Don't really want to do the old "test ride at a local shop then buy cheaper online" thing but that may be the only way I'm going to decide........