Your Garmin help, please

Hm, kinda tempting. It's obviously more expensive and not as svelte as the Edge 25 but the featureset's much more broad. The 35 and 35t support ANT+ for cadence as well, which I think would be interesting although clearly trivial to calculate when you're fixed!
I guess part of the bulk is because it takes AA batteries.
Good shout, I think, although the size of the Edge 25 is so tempting!

Very very tempted by that. the fact it still take AA batteries help swayed me over from the ridiculously short battery life.

Get the new etrex touch.

I did this (30 or 30t - it's hard to tell which I got).

Still getting to grips with the strange ways of these devices, but here's a first peek review:

Pros:
Solid unit. Survived a fall onto the road when I hadn't clipped it in properly.
AA batteries
SD card slot (as yet unused)
Only one button
Touch screen works
Bike mount clips onto the battery cover which has a locking mechanism to attach it to the unit, so even if the bike mount breaks you don't have to junk the whole unit, just get a new bike mount or battery cover
Does ANT+ to cadence and wheel sensor
Bluetooth to the phone (Samsung S3) actually works, mostly. You can have notifications pop up for SMSes and phone calls and it'll sync with Garmin Connect via the Android app.
Useful for non-bike stuff (it's not specifically aimed at the cycling market)

Cons
Battery life is atrocious - I'm hoping this is because I'm using oldish NiMH batteries (1900mAh Eneloop and 2650mAh Duracell) so need to do more investigation. Still, it hasn't lasted more than 2-3 hours for me so far which is near useless.
Relatively bulky and heavy
Screen is like one of the old nokia phone screens - hardly vivid or vibrant, but it is viewable in daylight which is better than lots of the modern screens devices have these days
Handlebar clip is a bit stiff - takes quite some force to attach/detach
It rattles in the handlebar mount. This probably won't end well with 10h+ per week usage with tyres at >100psi
I've had a couple of rides which simply refused to sync to the Android Garmin Connect app, blocking all syncing. Ended up extracting them from the device and uploading them manually using some hidden GC link I found via Google. Once I'd deleted them from the device it synced fine.
Managing the device with Linux is a bit of a black art, e.g. firmware updates: you just download the firmware update file, rename it and stick it in a particular directory on the device but you will struggle to find this documented anywhere.
No TCX support. Still figuring out how to get turn by turn navigation working from a ride plotted on ridewithgps.

So, not unhappy with it but not over the moon.