Out of all the guns mentioned, I've only used the BSA, Davys HW100 and and an FN19.
The Falcon was such a long time ago, I can't really comment. The BSA I liked, light, came to point well but didn't feel too well built as so many BSA's haven't for long time.
I really liked Davy's HW (thanks, mate), very well screwed together and shot beautifuly. Easy to use too but it just did not fit me. I'm 6'2, 14 stone and have long-ish arms.
I've handled the Daystate and have to say I nearly bought one but couldn't really justify the price. The high shot count and the way the gun handled near