Having had a Delta I can confirm what John and the others say.
You feel that the boat is capable of far more than you are. It was my first boat and I learnt (and still learning) a lot of lessons the hard way and the boat never failed me. If you’re going offshore then you need a boat that won't break. One issue with Delta is that, unless they have changed, are only making boats for commercial organisations.
My current boat is an 8.75 Scorpion with 300hp Yanmar which offers a very dry ride and I would say is a drivers boat. Mike Deacon went round the UK non-stop in the same length/power boat recently without any problem related to the boat.
Also look at Ribtec, as Alan Priddy, has taken the RIB profile higher and higher and he has always used RibTec (never been on one so can't comment).
Avon are quality boats but you pay one hell of a premium
Get yourself on a cruise and look at the boats and talk to the drivers. See who orders the first whiskey and you'll know who had a hard ride.
By the way I’m hoping to cross the channel this weekend and may have space on the boat. If your interested call me on 07973 343283
Regards
Mark