Any are better than none! The Spoc is a fine little tool. The only one that I'd avoid at all costs is the Nano Traxion, as that does not have a cam that can be locked open for reversing the haul. It's for crevasse rescues where you won't be putting someone back down! Releasing and lowering in a controlled way is an essential skill to master if you plan on carrying a progress capture pulley.
Mini, Micro, Pro, Spoc... they will all do the job so it comes down to your budget, features and size preference really.
If I had to pick one over all others, I'd grab a new Mini Traxion. Stays on the carabiner in use, highly efficient, but still small and light. If you are in need of something to put you to sleep, I did a short video (originally aimed at LCMLA holders) on the new Mini Traxion which you can see here:
www.peakinstruction.com
And at the risk of being slightly self promoting, there is another progress capture pulley related new video on my YT which anyone who carries one might wish to watch.
https://www.youtube.com/channel/UCEeN4aAfxzd1XffZg-pp4TA