To help you compare the very popular T series watches, T1, T3, T4 & T6 we have added a another comparison chart to the site. Please use the link below.
For the mountaineer in training then the T6 offers all the training features, compatibility with all the wireless PODs and altimeter and barometer functions. The T4 software will actually tell you when to train harder and when to rest, while the T3 offers compatibility with all the wireless PODs at under £100