ASUS has designed Sica for MOBA gaming - and supposedly features more responsive buttons than anything else on the market, since its buttons are separated from the shell, reducing tactile force for button actuation. Ignoring the factthere are quite a few gaming mice with similar separate buttons from the shell - this is a claim that's very difficult to test, at least by hand. It's possible that for a pro, there might be a difference - for me, not really.
On all other fronts however - Sica is still a decent performer, despite it not being as feature complete as some of its competitors.
PMW3310 is one of the better options on the market. By default, it boasts a 5K DPI resolution, and a tracking speed of 3.3m/s. Its implementation here is performing excellent. If not for the rather odd shape, and the MOBA blurb written on the official site - I would've said this was a mouse for shooter playes.
Important details like hardware acceleration - they can be tweaked via the software, and are almost non-existent by defaulty. The hardware is minutely tweaked, and the tracking follows through.
On desk - Sica looks interesting - a mix of polish and subtle design.
In hand - not as much. It's not bad - I did get used to it quickly, but unfortunately, I never actually got around the shape. The lightweight build and compact size makes it perfect for most claw-grip / fingertip users, and I believe it's designed for a hybrid between the two. However, I do have some problems with the oddly angular edges, and the overall girth. It's too slender, and the lack of proper rubber grips on the side are not weighing in its favour. If you move the mouse around a lot, you will feel slipping out of hand.
These could easily be fixed - just take the firm pattern at the back, and move it closer to the front - that would greatly improve the ergonomics.
As always, keeping this part short. There aren't enough buttons to use strings of macros and complicated commands for MMOs or games that require using half-a-keyboard. Instead, you're most likely going to look at Sica MOBAs, since it's lightweight and easy to move around, and shooters - where the excellent tracking will help.
Unfortunately, I cannot recommend it, at least not fully. The reason, of course, is the not so great ergonomic design. For shooters, more than anything else, proper ergonomics are a must, and when you feel the mouse slipping from your fingers (especially for low DPI players) - you have a problem.