Jamboo, I went to the one at Kilworth House too, very nice setting and some tasty food too!
Having been there and driven the RX350 (OK), GS450h (Amazing), SC430 (Awesome) I can confirm that there is no hard sell whatsoever. At Kilworth House you picked the car or cars you wanted to drive and they just put you on a list. You could then have a drink or something to eat till you car was ready. In my case I didn't have to wait at all for any cars other than the SC430 but it was a very sunny day and the car was in demand.
When you car is ready someone took you out to it and if need be they would talk you through the route you take and give a brief overview of the car you are about to drive. In the case of the hybrid (GS450h) the guy really explained the system in depth, and answered all our questions.
While we were waiting for the SC430 one of they sales guys from Leicester who I have spoken to in the past confirmed that Lexus are bringing out a convertible AND a coupe of the IS. Though from past experience from other car dealers I normally do a "I'll believe it when I see it" as I have heard so many different rumors about the convertible IS.