Hi folks,
This thread is getting interesting to me for the OT going on. I'm a tube amp user and my speakers are currently driven by a little tube integrated so far. I've tested many amps, for speakers and cans in my life, and I keep a good amount of both types of amps in my stash.
IMHO nothing sounds as clear, pure, natural, human and believable as a SET amp. But you need the transducers that can sound good and loud with less than 9wpc for speakers and a few miliwatts for cans with a highish output impedance. There aren't many SET amps for cans, and they have the same limitations, you need the right cans for them.
From my experience, any other type of non-SET circuit has always some tonal and resolutive flaws compared to SETs, but when things are well done and the implementation and parts quality is good, SS and tube amps tend to sound very very similar. Tubes still have an edge on timbric richness, but SS do have it driving difficult loads, be it low sensivity and low impedance speakers or cans.
Mark has a good point, SS is more convenient, saves you a lot of expenses and hassle looking for your "wonder tubes", but that's also a part of the fun for some people. I love tube swapping on my tube amps. But when you need power to drive difficult cans or speakers, IMHO SS is more adequate. Nevertheless good amps, either tube or SS, are expensive and finding powerful devices doing things simply right, requires time and money. If you spend big bucks on an amp and you want it to drive anything from 16Ohm to 600 and from 80dB/mW to 115dB/mW, you have more chances to find it into the SS camp than in the tubes' one.
Knowing a bit the D5000 I'd recommend better a good SS than a tubes one, but by no means I'm suggesting SS is "the way to go", just that you're more likely to find a good match and not falling short of power with "decent" SS than with "decent" tube amps. OTOH you might prefer that plus of richness and texture of the tubes, at the expense of losing grip and real control of the HPs as soon as you're listening to any complex music program, or want some loud listening.
To each one his own
Rgrds