I use it exclusively for shared hosting and feel like I have everything I need, nothing less, nothing more. It's a lightweight, no bloat, straight to the point, no gimmicky and certainly no bull**** piece of software.
I can sleep at night using the system, safe in the mind that it won't break or suddenly stop working. I receive an order during the night, Blesta checks for fraud, activates it immediately and emails the customer all the information they need. What more could you need for shared hosting? It really is a hassle free system and I've found requires less man hours to maintain than WHMCS.
Just my 2 cents