I find stuff like cosmos to be used mostly by lamers. Coordinates would be handy on the map yes, but then people ask for coordinates for quest items, when if they just read the damned quest and used their brains they would find them!! It comes with maps for dungeons too which ruin the fun of exploration. It also screws up capturing the flag on Warsong Gulch… A noob/meathead’s mod if ever there was one – try it out, most people will like it for what it does, but it’s what it doesn’t do which I don’t like – it doesn’t allow you to use your brain =/
Personally I avoid using any and all mods unless I really need to – the only thing I use is called enchantrix which basically says what an item could possibly disenchant to and ifyou disenchant somehting that has never been done before, it adds it to the database which you can upload for everyone to benefit from.
Auctioneer can also be handy if you want to track item prices to make sure you’re paying a fair price and it’s also good for listing multiple stacks of items, but as I don’t really buy much off the AH I just wear what I find I’ve not had the need to reinstall it.