I will generally agree with Dananuh, there are a few benefits. These do not instantly make you famous. If you stop with consistency then you will be forgotten quickly.
First benefit: Shows - a show allows you to group your content into one "show". Most of the time that show will appear at the top of all YouTube and Google searches. That is of course that there isnt already an established show with that name.
2nd: Search relevance. Supposedly 2 videos both being equal, one is by a partner and one is not, the partner one will be above the unpartnered one on search results. YMMV with this one
3rd: instant monetization: with adsense you have to wait to get approved and YouTubes terrible automated process often times will deny a perfectly acceptable video. Partners do not have to face this. Instead they get to put an ad up immediately by clicking 1 button.
Hope this was helpful. Smaller channels still need to bust their butts to get views. Partnership can help but its not a potion for instant fame.