Haven't heard the T5p; have heard a lot about it being "very harsh" though - the SA5000 can hit the Sun when it comes to the high-end, but they're never "harsh" - they don't ring. I'm somewhat curious about the Ed10 based on your comments. Then again, I've hated every other Ultrasone I've tried, so I'm very skeptical as well. Are there any cheaper Ultrasones that approach them in any way? (Like the PRO2900?).
Pro 2900 is a lot less sibilant than the Edtion 10 - Ultrasone created a bit of a unicorn with the Ed 10, nothing else in the
range sounds anywhere near as bright. They're fairly forward too - amp selection makes a big difference with them too.
Tubes are out in a big way - I've tried them with a WA22 and WA6 - they just
sound very 'off', tonality in that instance is just wrong.
In my experience, the owners of Edition 10's are flagship mongers - they have it all - HD800/LCD3/W5000/PS1000/T1
, a STAX of sorts (usually MkII Omega or SR-009 - The Edition 10 is usually a way of crowning the collection.