Yes, I uses the slots all the time. I have just filled all of my non plus slots and am onto the extras!! XD There is only one Enistachia and only one User behind him. Oh, and only one account used by the user.
I make tons of different avatars, I have all the slots (without plus) full. Sometimes I might want to use a girl avatar and sometimes I might want to be a warewolf knight....or a giant soccerball with a bomberman head. Point is I get bored without variety.
See that's how i do it. I guess I am too lazy. I just can't see myself going through the application process each time. Getting a new email adress, unless I can have all my other accounts on the same email as my Enistachia account then possibly I would make some alt accounts. I am talking about creating logins, using emails and addresses, and regions. I knew someone who, every weekend would tell me to add this account, it was their other avatar. After four weekends in a row adding these alts I decided that it was silly and I would only keep one of the identities.
That's how I do it, too. I can't afford having multiple IDs with cool items, so I just create as many as I can with the one I got. I had 46 of 48 slots filled, but did some housecleaning and brought down to 41, which isn't much different. I did rearrange them where I have my more used avatars on top now. As you can see, the eyepatch is my most common used item as it's been my signature look, since the 1st game I owned that allowed user creations, WWF Warzone. It's a tribute to my favorite video game character, Sagat from Street Fighter. The one with the shades is my "self portrait".