In my haste, I now realise I didn't really answer the original question. The T7300 is by no means a bad box, even if it may have been superceded by the T7650. If you are familiar with the Vestel SD PVRs, then you will instantly be at home with a T7300 - the software and user interface is very similar, but enhanced obviously. Many of the problems that plagued the old SD software are gone for the T7300.
This may change, or may have already changed, but a pro for the T7300 is that it uses the HTML based iPlayer, which has the high quality option. Whereas the T7650 has the red button MHEG iPlayer which IMHO is not really as good, but this is the "official" way to do it which is what the Sony and Digital Stream boxes use too.
The main con would be that it is unclear whether the software will be developed further. If you have any specific questions, feel free to ask. £114.99 is certainly a relative bargain considering that is now cheaper than most of the SD PVRs.