SP10 is a classic. I have had one for 40 years. It has given great pleasure. It was state of the art when introduced. Although very accurate and detailed, it is a but soft for some relative to today's high-end amps. You could call it a 'classic' sound and it is very good it that is your bag. SP10 is all valve. SP11 is hybrid. On introduction, many reviewers mourned the demise of the SP10 as the transistors did change the sound.
Yes, capacitors and valves have been replaced in my SP10, but it is not my main pre-amp now; I have a Ref 6. Removing the rose coloured specs, Ref 6 is clearly a much better pre-amp than SP10. But when I listen to the SP10 in my second system (all iconic old pieces) there is unmistakenly a warm pride of ownership and reminiscence.
So there you go OP. Unless you are a fan of an older warmer sound or, like me, are a bit of an anachrophile, go for the modern amp.