I think you got a good tire with those Avon's . Sounds like a good price. To be honest even though all the above tires mentioned here are better than stock. The stock IRC's that came with bike were more than good enough for everyday road riding.
Based on that UK review, I decided to get the Avon AM26 road rider. I hope I didn't go wrong. Picked them up from Canadasmotorcycle.ca for about $228 + tax (front and rear)
keep an eye out on the roadrider for cracks..heard lots of bad stuff about them...sorry for the bad news
http://www.thegsresources.com/_forum/showthread.php?t=140853&
I will vouch for pirelli angels. 20k km & good wet & dry grip. It u can out ride that tire on your 250 i'll give u a free coffee.
I've ridden countless sets of tires Dunlops, metzlers, bidgestones & that is the best bang for the buck
first off these tires are not available in Ninja 250 sizes, and you're only getting a single tire for $140...