best wow version trinity trinnycore

Hi Everyone i have a question i see 2 version on the main site

i wil open my server soon but with version should i pick where not too much bigs are in the server

3.3.5 and 6.x.x

but with version is the best of these is 6.X.X al huge bugs fixed or can i better pick Wotlk Version for now ? of is there still much work to do on version 6.X