First off -- cost.
The Vivosmart HR is $150. So in that sense, it is certainly cheaper than going out and buying a 235 for $329. Is the 235 worth an extra $180?
I would have thought a 620 in pretty good shape would have sold for close to $100 on eBay, but the market seems thin - I only saw one used device getting bid on - and it was only up to $30. So it isn't prudent at this point to expect the 620 retains a ton of value.
I think there's real value in the 235 over the 620 + Vivosmart HR. Here's my list:
- A better accelerometer for indoor treadmill running. I find the 235 to nail it as well as a Garmin footpod (which retails for $70) when I run inside -- more accurate (closer to perceived pace and actual pace on treadmill display) than any other Garmin I've owned. My Vivosmart HR was unusually bad on this count - 20% off the actual count in miles. If you do a lot of treadmilling, this accuracy is a significant feature. The pace and HR below are from a treadmill 5K.
- It looks more like a watch than a running watch. The 620 watchface and color scheme weren't business friendly - I like a watch that isn't noticed as a running watch. The 235 is black, sleek, and is not noticeable as a running watch.
- Garmin Connect IQ watch faces. There are some really functional and even approaching attractive free watch faces on the storefront (and a bunch of other widgets to play with). If you like gadgets and fiddling with this kind of thing, it's a lot of fun.
- One watch to rule them all. It's a lot better to have one device to charge and wear, rather than a band and a running watch - much more convenient.
So there you have it. I'd say if you are a regular runner, it's a no-brainer - go upgrade. Welcome to 2016.