I picked up a few IXO Junior planes, mostly because the price was right. The panel lines are way too deeply engraved on some, but the Yak-9 and the Il-2 weren't too bad. It's too bad their quality isn't better as they have a great selection of unusual types out.
I've found that the best IXO planes in 1/72 are the Japanese ones. For some reason, the Oscar, Tony, and N1K2 that I have are all excellent, while I have given away most of their USA models in favor of Hobby Master, Dragon, etc. The LA-7 and Yak are not bad either.
I used to love the Matchbox 1/72 models, and have all of them (WWII) - I wish they would have continued the line . . .