I've always thought that the Runemate botstore is really hit or miss. There's a lot of great bots on it, but honestly there's a number of junky or downright broken ones. For the most part, most of the premium bots are pretty solid. Especially from specific groups (Prime, Hexis, what's left of Regal) or specific users (my Cuppa bots, Dark, Maxi, Dan, Awesome, Divine, etc etc). This is by no means an exhaustive list and there's plenty of other good bots/authors. Also I say that most of the store's premium bots are solid, but there are a few free bots that are either good enough to be premium but just aren't (eg Dan Blast Furnace) or are in development/partially complete and will be premium eventually (a few of my bots, Dark Quester, Awesome Slayer, etc etc), so don't count out free bots entirely.
Honestly I'd just trust the default sorting of bots to get a basic gauge of how useful/good they are. If you're looking for a combat bot for example, there's a ton, but the top ones are used a LOT more than the lesser used ones. Of course the lesser used ones could be better/better value, but it's a good starting metric.
There's definitely some broken/partially broken older bots, which can make it annoying to sift through, but "last updated" by itself doesn't indicate a bot is bad or outdated. Most of the old content in OSRS has never been changed and for most there's nothing that really needs to be updated. A lot of the old authors have gone semi-inactive, but their bots are still largely in a good state. Plus the nice thing about Runemate's payment structure is that you can try a bot for a few cents and figure out pretty quick if it sucks. Cloud still updates the Runemate client itself as needed.
