I can only add my experiences with the basic RIAA phono stage. I originally bought it to partner the Decca London Super Gold I was using at the time, having heard that Glenn designed his stages around them. Indeed, this pairing made a very acceptable noise indeed :)
When I sold the Decca I have to admit I wondered if I'd be keeping the Croft but as it turns out it's way more than a one trick pony. It's currently making very nice tunes with my SPU (by way of an Ortofon SUT) and in fact I prefer this combination to the Decca.
My stage was modified by Glenn a few years ago to include 2 inputs, he turned it around quickly and even screenprinted the front of the unit around the new switch! I have rolled some PSvane tubes into it and this has brought about a more even handed feel to the sound, the original JJ tubes can be a little rough and ready, though exciting and involving.
Hope this helps. Ask me anything you can think of :)