Thanks a lot for all replies...
I actually used the Avalon U5 and while I can see it's positive points, I really don't like the sound that much... Not really my definition of warm.
Played through a Demeter pre some time ago, but it's very hard to come by (europe) and a bit expensive, especially taking it to some gigs...
I must say I play in a soul/neo soul setting (with a P bass).
The studio has reasonable DI's and pre's as well as compressions, but I would like to have something of my own, also for home recording.
I think I'm going to check out the presonus, and the art, and probably then go for the best option of saving my money and getting a more expensive 'real' preamp. (@bongomania, thanks for pointing out the renting option, that's problably best for the next studio session)
yea...
while it might seem like a worthwhile investment again for the home studio, i gotta be honest and say its quite rare on a session that i actually am able to use my own DI, cause alot of engineers/producers are soooo adamant about using their gear. so unless you're preparing your own home studio rig, i'd save your money for other things. like rent!
but if you are really serious about gearing up for your home studio, to be honest, forget everything i said in the previous post...

bottom line, dont go w/ cheap gear. the differences can be dramatic, and your demos will be taken that much more seriously. i learned the hard way. by wasting a ton of money on crap sounding gear.
with that said, my demeter tube DI and my summit td100 have both outshined anything in its class. sooo versatile for bass, acoustic guitars, upright piezos, heck, i've used the td100 for direct clean electric guitar! shh, dont tell my friend, but i think the demeter sounds better than his UA solo/610!
either arent as gooey a sound perse like the REDDI, but again, for that one DI, you dont necessarily want something that overaly colors the track. both the dem and the summit really enhance anything i send thru 'em w/ a nice 3D tubey glow. the REDDI is a nice thing to have in the tool shed for those times when you want goo and glop, but its like owning a bread knife when you really need a nice 9" chef's knife.
but do a search, and you'll see we've beaten the affordable but awesome DI thing to a pulp around here.