I have a set of Reuben Heaton Flyweight Mk2 scales and I think they are great. I test them all the time, especially after a good fish, I'm pretty obsessed with it. After Dan's double barbel I tested them on some known weights and they were to-the-ounce (sigh of relief from Dan). The problem is the first 8oz, it's kind of a dead zone, after 8oz they work - they stick before it - I'm not sure if it's a design flaw or if it's just mine.
Another trip out after a pound-plus roach this afternoon, and this time I decided to use bread flake instead of maggots to deter the gudgeon (last time they were smashing up the maggots before the roach could get to them). It didn't work - I just got bigger gudgeon - the first was a whopper, I tried to weigh it but it wasn't going to work. The second was bigger - Dan informed me he had a ruler - 6 1/4 inches, that's a big gudgeon!
The third went 7 1/8 inches, I wish I had scales that could have weighed it! It was really wide across the back and was the biggest one I've seen... I'm going to get scales that can weigh them next time. They must be close to the record!
No roach showed, and once darkness fell the bites dried up. Me and Dan hit some summer barbel hot spots and ended up with an eel each. Some people are still catching barbel, we're not... Time for a rethink...
[Edit: Jeff Hatt of Idler's Quest has done some interesting research into gudgeon size here]