Just changed from orange to BT and have a HomeHub 3.
Early impressions are that my orange hub linked to my PC faster than the BT jobbie. I'm forever having to 'reconnect' the Home Hub to my PC. It's early days so I'll have to wait to find out if things settle down.
Some of the earlier BT HomeHubs were known to have problems (don't ask me what they were, I've read this on another Forum) but the introduction of version 3 was meant to have sorted it all out.