it sounds bit like its slows down because it need to clear some ram or storage. the reboot helps but enough if it has no room to move. do you have any cleaner tools to check and clear the ram or the cache? it can build up over time it to slow and struggle to process a bit you described, and a reboot will move files around tidy up a bit, and boot up looking better than it was. I would start there. Not too many cleaners around for these. one called defsquid, silly name, it can close running apps, clean the drive and release memory and virus scan. Its also free. I hope i wasnt just babbling on stuff you already know and got it covered. if you want to try that app and cant find it, let me know.