Yeah, it is a cool box. I got too frustrated with mine after i didn use it for 6 months. I forgot all the button combo’s and double clicks that i just sold it. hehe.
Sounds to me like someone has missed out on the awesomeness that is PLAYS FREE. Using plays free allows clip style playing on the OT 
If we look at Ableton v 1.0, what we got?
- Clip launch grid
- Unlimited audio tracks (limited by computer specs)
- audio clips not limited by RAM
- realtime timestretch/pitch shift via warping
In this regard, quite a lot of boxes out there already qualify (besides the dynamic track count thing). So in order to really answer this question, we need to establish which version of ableton are we referring to? 
It’s about the optic of features too.
The 707 grid view resembles abletons in a good way.
I guess in the end you can’t compare the features alone, but the look and how you use it too.
But: If someone loves ableton, he should use it. apples and oranges.
Agreed, my SP-808 from 1998 does time stretching as well…although hoo boy it takes some time to calculate.