Wasn't impressed with Senheiser either to tell you the truth.
Doubt the Bryston will be competitive price wise in the UK compared to the Schitt so then you'll have to weigh uo how much you value headphone listening.
Which preamp/integrated do you use and does it have a headphone o/p?
One of the reasons I bought the Schiit Lyr was because it's relatively so inexpensive, and wouldn't bust my budget in case I decided to buy the BHA-1.
I have a Bryston Preamp and it does have a headphone jack, which in terms of sound is virtually identical to that of the Grace Designs m902, which costs more than the expected price of the BHA-1. The Lyr, with the volume turned up high, has a hum (which probbly is something in my house wiring), but even then, to my ears sounds better than the Grace. The Grace can sound closer when played at high volumes, but still lacks the musicality of the Lyr.
The Sennheiser HD800 is great if you're looking for accuracy and are a sound engineer or in the recording business. I am in neither of these categories. Enjoyment is my measuring stick. I didn't know how dry and unexciting the HD800 is until I bought the LCD-2. The LCD-2 doesn't have the HD800's wide soundstage, but seems to be very precisely defined. These cans have an intimate sound, and the bottom end is incredible - deeper than I've ever heard, and very punchy.
So, getting back to Bryston. Will the BHA-1 sound as musical as the Lyr driving the LCD-2? Will it add excitement to the HD800? If there are differences, will they be, as you point out, significant enough to justify paying more than twice the price of a Lyr.
The answer to all these questions, as always in audio, are entirely subjective. There will be listeners who love the HD800 and Grace, and hate the Lyr and LCD-2. And still others (often myself included) who are ready to pay big dollars for small but wanted differences. Fortunately, I should be able to demo to BHA-1 to come to some conclusion I'm prepared to live with.
However, whatever that decision might be, I still haven't figured out how to split my time between a great main audio system (PMC MB2i speakers, 7BSST Squared amps), and a very good headphone setup, which becomes even more problematic when you own more than one set of cans and HP amps.
BTW, the LCD-2 rolls off in the very high end, where at first it seemed that cymbals were just not strongly presented. But I switched to better interconnects from my BDA-1, and now I'm getting a better result.
Dave