SABR is terrible if that's the one that has 1 movement point and has to set-up to attack. The extra range is completely worthless since you can't shoot over terrain. And you have to upgrade them to remove the set-up need.
On the other hand, CARVR is handier than you think: if you bee-line it, it will be ahead of most enemy units at least for a little window.
The tech-web is all about bee-lining, now. Bee-lining was always important in Civ V, like when folks would bee-line to artillery and just start taking city after city, or bee-lining composite bows. But now? Now, in C:BE, if you don't bee-line to something like CARVR it's worthless, but if you do rush to it, it's a lot more powerful than you think. I found this out with the Battlesuits in the Purity track already: don't bee-line to them and they are terrible, but if you do, they can take a good number of cities for you.
CARVR is one of those units you need to bee-line.