Was very disappointed with 220 show at Sandown - went in there with a genuine requirement (was looking for a new bike) and found nothing that wasn't 1500 quid plus (and very few people even prepared to talk to me). I can't be the only one that doesn't have thousands to spend on a bike!
Best was the smaller stands downstairs that was so badly signposted I didn't even see it until I was on the way out - but at least they were interested in talking to you. Not one I'd go back to. Might take a look at Excel this year.
A local tri coach suggested http://www.briancalkins.com/HeartRate.htm to me, which is better than the 220- formula but not as good as getting it tested properly. I've used that as a best guide for now - trying to learn to run slower, as I've tended to just go and bash out my training runs before. Getting sick of getting my Garmin beeping at me, but that's what I need.