Well i had the sia025 on demo from Richard for a few weeks, as i was looking to move my 552 and 500dr on, at first i liked what the vitus did, but this comes with its own problems.
I found i only really liked it in class A mode, rather than A/B.
In class A it gets very hot.
You cant really leave it on 24/7 in class A, because its to hot, use lots of power and be worried about it.
So leave it in standby, this then for me was a problem as it took atleast an hour before i felt it started to sound as it should, and really it got better as move time you had it on, this felt like i had to try and work out each day, when i was going to listen, this just didnt work for me.
Lastly i found myself only listening to certain tracks, i didnt realize this for quite sone time, the reason was because these tracks suited the sound and the others now didn't sound so good.
But the sia025 could sound fantastic, nice detail and super wide.
But for me in the end the Naim still had it, i like its punch, its fast sound, it can't match the vitus sia025 for certain music, but lost out then on others to the naim.
I like the way i can just sit down and go, no waiting.
I certainly dont miss the heat the vitus pumps out, as it like a radiator.
I decided to get my 552 serviced and its power supply dr'ed and this has pushed it to new highs
If i was ever going to revisit this, then i would try the sia30 this time round, as this might bring more to the party over the sia025, and have a more off a sound i like, but in no rush to try, also i see, quite a few owners off vitus dont stay for long, a year or two and they move it on, that also worries me, as vitus doesn't hold its value that great, especially compared to Naim