When I understand it correct, SparkyLinux is RollingRelease based on Debian (testing)?
For Siduction (based on Debian(unstable)) or Debian (unstable) itself there is often the warning that sometimes the system crashes after an update. So you have to keep an eye on upgrade warnings etc
What is about SparkyLinux?
How stable is it? How often does the systems (the repository snapshot at a specific time point) don't work?
Welcome. Saw your post elsewhere. I have siduction on a netbox and sparky on a netbook. In the very or fairly chaotic time of the GCC transition awhile back - it was more difficult in Siduction because it was on the edge of a vast upheaval of new libraries and the affected programs. It was easier here in testing. Actually my first apt-get dist-upgrade was in sparky about 3 weeks after the transition.
There are slightly fewer upgraded programs that come to testing because the easiest to find bugs are worked on in unstable-sid. Security comes to testing last, but the ride is much smoother.
Debian testing distros have come and gone. This is about the only forum that specializes in problems encountered to testing. For me there is three choices for an OS. Debian stable, Sparky linux for debian testing and Siduction for unstable. I went to testing during a freeze, got even better at my command line (I am not an expert) and years later went to unstable for my favourite box.
No one to my knowledge has as good a testing release as here. This is a very good place to gain skills and learn linux. And you can lurk at Siduction for the upgrade warnings for what might happen to testing in five days.
Peace out, Mark
In my experience sparky is VERY stable (even though it is testing). I have not had anything break with dozens of updates. It's rock solid, fast and helped me to really learn a whole lot more about linux in general!