Personally I think the introduceyourself tag, since its inception, has been the greatest driver of new users here. So long as the post is legitimate, it can give a new user a head start, give them more Steem Power, and give them some Steem Dollars too which they can then learn how to use.

I'm below whale-status, but generally I try to upvote introduceyourself posts if I can tell they will be a valuable contributor. I'll read or at least skim their post and see what kind of person they are and if they are bringing themselves here. If they post an image of themselves I'll google reverse image search it (browser plugin makes this easy). I'll check their post history and see if they've made other posts or commented on other posts. 

I think #introduceyourself posts are good for this site, all the Steemit-fluffing circlejerk posts on the other hand... (I am guilty of these in the past too, but trying not to post anything Steemit related unless it's important).