HRM/GPS - to upgrade or not, that is the question

I admit it, I'm a gear nut, and I like new and shiny, so I'm a bit of a sucker when it comes to the latest and greatest.

Here's the thing: I have a Garmin 910XT, and have had it for about....4 years (I think). It has served me well and continues to perform. I have cadence/speed sensors on all my bikes, and it works nicely with them, the heart rate strap works well too (though I do occasionally experience frustration where it seems highly sensitive to where it is on my torso, sometimes showing my heart rate up around 200, then back to 140-150, then down below 100... :s ). It does reasonably well in the pool counting laps, so in general, I'm more than happy with it.

But then....Garmin releases the 920XT. Full of new fancy awesomeness like wifi, bluetooth, better capabilities for metric collection, the super cool tri HRM strap that lets you track heart rate under water.....But with the tri bundle, and the poor exchange with the Canadian dollar, it's about $860 CDN. That's a lot of coin for what amounts to tri training bling.

Any opinions as to whether I should bite the bullet or not....? I've got 2 races booked this year, and there is this one down in Cozumel in November I'm thinking about... ;)