Having used both recently I have found the Global trainer to be a more versitile when it comes to setting up multi screens and data fields. you can personilise the 5 display sreens in performance and multisport mode. Something which was not possible on the 310 I tried. Although a similar size I found the shape of the Global trainer was better and despite having small wrists the shape and size were good and forget its on the wrist.
Had one of these for about 3 days after buying it from Runners need in London. Great watch i had been looking at the 310XT also as they seem to have similar features. The Timex Global Trainer is spot and V qucik at picking up GPS signal withing 15 seconds by my front door.
Also the size is the same as the 310XT and I think a better shape, the weight of the products is great very light and you dont even know its on the wrist when training.
As always with technology there is always mixed reviews. I bit the bullett and am very pleased with the Timex Global Trainer.
The online training system is also V Good.
I say make a fair comparison to a product with similar features such as the the 310xt and the Timex wins for me every time.
I went into Runners need and tried both the 310XT and Global Trainer on my wrist and i honestly felt know difference but the Timex looks a better watch and not like a computer for sure.