I loved it! And still do, but sadly I moved to a RPi/XBMC/transmission/SickBeard/Couchpotato setup which was very easy to setup using xbian, thus not using showRSS anymore. The raspberry is a bit underpowered (according to me) though, so I'm thinking about replacing SickBeard with showRSS again. Pitty there isn't a good & easy way to do it. (not that I'm afraid of doing it all manually).
Perhaps also interesting, before using showRSS I was using TVshowsApp (http://tvshowsapp.com/).
Something I'm missing from showRSS btw, is the ability to browse trough all episodes/seasons and be able to select an episode/season to be added to the RSS-queue, so my downloading box would fetch it next time it checks the feed. But than, showRSS does one thing very well, so I'm not sure more features like that would be helpful for everyone.