I'm no expert on Trans but have noticed them around on ebay quite a bit and have looked into them. From what I've managed to gather, Choc used to be an OEM for Trans, and maybe there is still a relationship between them, but nowadays, Trans also seem to have their own factory in Thuringia. I have also read of links between Trans and F2 and Volkl, but not sure how credible that info is.
F2 and Volkl being two of the biggest Europen brands, it wouldn't be too surprising if they were OEMs for any number of less well known brands.
Also, both Trans and F2 have "Twistboards" in their lineups, and no other snowboard brand does as far as I can make out, so maybe F2 OEMs the twistboards for Trans, or maybe Choc or AN Other OEM makes them for both F2 and Trans. But this is conjecture.
Anyway, Choc has some nice looking boards in their lineup, including a titanal race board, and they have been around for a while, so they probably know what they are doing. So if they are still OEM for Trans then the boards are probably decent.
If you see something that suits then maybe worth a gamble, but they are not priced much lower than comparable F2 boards on ebay.de from what I've seen.
Check out these links:
www.choc.cz
www.trans-snowsports.de