MIDA is an excellent weapon and probably the best scout rifle for the crucible. It and the Crypt Dweller (along with any lesser quality rifles with the same block) still get 4-shot kills but at a faster rate of fire than other 4-shot rifles. Unless you get an incredibly amazing Crypt Dweller roll, however, MIDA's huge magazine, Third Eye, boosted movement speed, and excellent stability and reload speed will make it the obvious choice. If you're more of a PvE guy, MIDA is still an exemplary scout rifle but maybe not the best exotic. Kinetic damage is hard to justify with the amount of elemental primaries we have now. Still, the exotic effect and Lightweight in tandem make the Abyss in Crota's End much easier and makes the tedious patrol and story missions go by a little faster.