Simon,
IMO, the HK is a somewhat different animal than virtually any other model recommended in this thread, so it will come down to your personal priorities. The HK power amp section is a true high end SS design, similar in many ways to those found in Electrocompaniet amps (they were designed by the same person). As far as I can tell, the execution is first rate and the HK 990 will handle most speaker loads very gracefully and without complaint. Personally, I doubt that any other SS integrated amp in your price range will be meaningfully superior in this respect.
The pre-amp section is where this choice will either win or lose for most audiophile types. It can be used as a traditional high end unit in direct mode. I thought it sounded very good this way in the lengthly home audition I conducted. I didn't compare it to Marantz, but I did have the opportunity to compare it to a my Bel Canto and Pathos integrateds with my SF Cremonas. I would honestly be hard pressed to tell you I heard much difference between the Bel Canto and the HK - tho I thought that the Pathos was a somewhat different sounding animal.
However, when used with the DSP engaged in a system with subwoofers (a pair of 12" Rythmiks) and Maggie MMGs, the HK really shined. It replaced a high end Onkyo pre-pro and an ARC VT 130SE and sounded very, very good in comparison. At the price, I felt it a real bargain for such an application.
My bottom line (per my previous post) is that the HK probably provides unmatched flexibility relative to the universe of high end integrateds. IMO, it's very, very good as a traditional unit, but absolutely great when used with sub-woofers. Since your speaker choice is TBD, I thought it was a particularly appropriate recommendation in your case.
BTW, I never had the chance to buy the unit as HK discontinued it before I pulled the trigger and I no longer buy used gear.
Good luck.
