I have pro match ib's, first batch were 1.23's i use it for stock racing. they get better on the second charge. lots of punch. I just received the latest batch at 1.242 to 1.247 I will cycle them about 3 or 4 times then use them at the tamiya finals. they seem to get better as you cycle them. no shorted cells so far, nor drop off during the 5 minutes.
pro match also includes hd single cell shrink wrap with you cells. for 10 bucks they will even build them for you. I build my own because I am cheap, but it isn't my fav chore.
the ib's are excellent cells and durable. I will be keeping these for a while. I don't know how much bigger these cells are agoing to get. I had to dremel my chassis to fit these. I heard them say several years ago that they will go to 5000s. i'm sick.