i started it because wallet began to freeze very often for a long time and I decided to reduce the size of wallet.dat (4 mb now)
with Linux, I started experimenting because subjectively it seems to me that synchronization there is much faster
Yes, that's my experience too. Immediately after startup and at arbitrary times the GUI is so sluggish that it appears to freeze (even with iguanadon1's PoS optimisation). I haven't found it to be
unreliable, just very, very slow for a while after initial startup but if I let it run for a while, the response improves after it's finished its initial staking frenzy. The latter is an unfortunate but obvious side-effect of running a PoS v1 coin where staking isn't tied to the time online but to having UTXOs. The Slimcoin community (as with the Peercoin community) has shown no interest in moving to a PoS v2 staking kernel (a la blackcoin) where the node has to be permanently online in order to accrue opportunities to stake.
Cheers
Graham