I've successfully used both Terroc 330s and Roclite 315s (both non-goretex) for a couple of years, so when the 390GTX boot came out I thought it looked great and ordered a pair in the same size 9 as fit me for both the others. When they arrived they were massive, slopping around on my feet, and I sent them back. Later I got hold of an 8 & 1/2 which seemed to fit a lot better......
I used them over Christmas for a couple of very squelchy days in the Moelwyns. The good news was that as far as waterproofing went they were as good as wellingtons. The bad news was that in many other respects too they seemed about as good as wellingtons!! In particular the forefoot just seemed incredibly sloppy and insecure, and it's a faff to try to adjust the lacing along the length of the boot to be the right combination of comfortable and firm where needed.
I used them again this weekend for another shorter walk, and tried a much thicker sock, which helped a bit, although the ground was a lot gentler too which may have had as much to do with it.
So I'm going to persevere a bit more but I fear they may turn out to be a mistake, which is a shame because they're beautifully light and the Roclite sole is good on a mixture of terrain.
I know fit is everything, but for me, compared to other Inov8 products, it just seems like this time there's something, and it's hard to pin down exactly what, that they haven't got quite right...