Hi,
Actually, it does. The information about recording is not related to the PVR part but to the analog input analog to digital conversion and encoding in MPEG-2 (en MPEG-4 coder is too expensive).
As for the TNT HD you have in France, there is "no" issues (at least related to the MPEG-4 format) since it is just a .ts dump of what is received on your aerial and demuxed so that you only keep the program you want.

By the way, I am also pretty disappointed by the firmware. I bought the PVR with the intention to replace my LG MS450H (I was so unhappy about LG firmware follow up) which has the same or very similar chipset, because of its too old and buggy firmware. Result? Today I exclusively use the latter to record DTT SD/HD, and I only use the AC Ryan box as an (expensive) NMT.
At the beginning I tried to tweak it (the same way I did with the MS 450H thanks to a french/spanish community), but the AC Ryan is more "closed" than the LG's, and the staff is banning to easily (I was) from forums to keep trying.

Bon courage,
Matt

PS: en résumé, il enregistre bien au format natif la TNT HD (et idem SD), sans réencoder et donc sans perte, les infos sur le MPEG-2 sont seulement pour l'enregistrement sur sa prise analogique. Mais la box n'est pas si bien que ça... et le firmware n'est vraiment pas au point et peu mis à jour.