http://www.dcrainmaker.com/2015/06/garmin-edge-20-25.html
Cheers!
Lack of 1-second recording & Tempe support ... However both of those could be added in software (if Garmin were so minded)
Fantastic! Weight weenies finally get attention after years of post-Edge 500 neglect.
However, I fear that certain marketing decisions are crippling this unit. It seems to be marketed at the recreational market but the 8 hours claimed, 6 hours realistic battery time aren't enough for most century riders. And people at below the century level are likely to be happy with their phones.
What it IS good enough for is road racing. And with the smaller - simpler - LIGHTER design it's ideal for that. However, it's crippled by 2 design decisions:
1. smart sampling only: this is bad for Strava segment timing (maybe Garmin connect timing is better, but nobody I know around here uses Garmin Connect segments)
2. no power meter support, despite ANT+ hardware: this just seems silly. You don't need to to display a full suite of power metrics: just show watts, and absolutely record the data.
I do regret the lack of a barometric altimeter. The above 2 + a barometric altimeter is a sure sale. I'd even give up 10 grams for the altimeter. But that's just my preference. Road racers/hill climbers/Strava KOM hunters don't "need it". However, the smart sampling + lack of power meter support are fatal.