I've never had an issue with the Synchro 800 shutter in my Chevron once I serviced it. The biggest issue is that is has a set of blackout capping blades behind the normal shutter blades and since there are only two of them, they have a lot of overlapping surface area and any oil that gets on them will cause them to stick heavily. This is the same issue that often takes out the Synchro 300 shutter found on the Signet 35 since that also only has two blades.
I don't advocate putting lighter fluid into the assembled shutter, as that is likely to migrate oils onto the capping blades making the issues worse.
Other than that, the Synchro 800 is a derivative of the Supermatic and many of the internal mechanisms are the same, they're pretty easy to service. Also, of the leaf shutters I've tested, it's the one that got closest to it's theoretical maximum speed, with 1/800th measuring as 1/770th.