Thanks for the suggestion Elephantears. I've read about the Alabaster a couple of times on here, so am intrigued for sure. The thing is it's not punchiness or vivid mid-range I'm particularly after and I've tried a few amps now and getting a bit tired of the process, although it's been mostly fun. Maybe I'm slightly unusual in what makes me tick.
So far, I've also tried Nait 2, Nait 5i, NAC72/NAP140, Exposure XV, Rega Brio-R (modern shoe box version), Creek 4140 and Linn Majik-I (LK type). I'm pretty familiar with modern Linn amps too, all the way up to Klimax.
Coming from Linn, I'm quite sensitive to anything slightly out of tune, which is where the original Nait and Majik-I score well. But I'm also sensitive to close syncronisation/connectedness between all the musicians, which is where all the amps do pretty well, except the Majik. The Nait 1/2 and Creek are best at this, to my ears.
There was 'something' about the 72/140 that I found fatuiging/too full-on, although it did mellow a little if left powered on all the time. The Exposure was a very good all-rounder, but something odd about the bass - maybe a bit out of time with the rest. The Majik sounded too HiFi and didn't bring the performances together as a whole. The 5i was good but not really tuneful enough for me. The Brio-R was perhaps the best all-rounder, but ultimately, wouldn't make me want to listen to music as much as the Nait.
We're all different though and these are just my preferences. The past few months has really emphasised the importance of listening to equipment in your own home, and I'm fully open to the fact that some of these conclusions could have been different when using other systems or listening rooms, but you can only do so much before getting fed up with it all.