I exclusively use Ascentric. Why? Very transparent charges - 0.25% platform charge (reducing to 0.1% for holdings in excess of £1m), and we can more or less request any fund to go on panel (and usually obtain at substantial discounts).
Clients understand the charges very easily, I can describe them on the 'back of a fag packet' if I need to - I can't get my head arouns Standard Life and others, and neither can my clients!
Also white labeling costs just £300 (one off).
I think they are excellent. Admin wise they have a few teathing problems as they grow, but generally I'm really impressed.
http://www.ascentric.co.ukRegards
Colin