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:
Solid unit. Survived a fall onto the road when I hadn't clipped it in properly.
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)
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.