Phil
I don't have an 'S' I have a 'N' - but I do also own a VFR 800i (2001 'Y' Plate PRE-VTEC) & I'm certainly NOT old before my time - just wanted the best all-rounder in the world. . . . . . ever !!
There's no comparison between the SV & the TL - it's like comparing a 'road-trained' horse with a bucking bronco !! If you liked the TL because of it's 'kick you in the a**' attitude - you won't like the SV.
BUT, if you want a (slightly) 'softer' (more) refined, all round V Twin, then it's the kiddie for you.
As for pillion - well the wife is certainly gonna notice the difference between an SV & the VFR - 'nuff said on that subject !!
May I suggest that you also (if you haven't already) log onto
www.sv1000.zyns.com where they deal purely with the SV1000.
As for prices - can't help you there - don't know anything about good or bad prices on the 'S'
I haven't heard of any major probs with the K3 / K4 bikes - don't think there is much difference between them other than the K4 was available in the dark 'Gixxer' type blue colour which the earlier ones weren't & the word 'Suzuki' on the tank was replaced by a single Suzuki 'S'.
Best of luck bike hunting - let us know how you get on / what you decide on