There are a lot of people that will agree with you about the Samsung V+HD, but the sad fact is it is very much yesterdays technology. The boxes went out of production in 2011, so all the ones circulating now are 2nd or even 3rd time refurbished units. Some come out of the shop with reliability issues.
Also, the lack of an internal internet modem means you are stuck with no apps, some of which provide additional channels or facilities you may be paying for on the TiVO box.
The best option is really to upgrade to TiVO (you would have to do this anyway if you made any change to your core package now). Phone & talk to Retentions (150, option 4 then 5), & see what they can offer. There will usually be an activation charge for the new box (it should be self-install) & may add £5 a month to your rental, but if you speak nicely too them who knows what you could come away with.