Hello, I currently have a lot of Logitech older gen keyboard/mouse and I really like them. The most advanced one is MX Ergo, which helps a LOT with my wrist pain. I really like the Logitech flow feature too because I can hop from my drafting laptop to CAD laptop hooked up to big screen anytime. Now, MX Ergo is awesome but trackball does have its limits and I do switch to Logitech M705 occasionally and I always travel with an M570 as a general purpose mouse. Now, I want a mouse and all I really care for is for it to work with Logitech flow because as much as I tinker with my computer a lot, it's just a nice feature that doesn't require much extra effort from my side and it saves time. Recently I tried to get a Master 3 at a local auction and that went over the budget I had in mind and I looked at a local supplier and I see M590 for ~40USD, M720 for ~55 and Master for ~90USD and I am also going to get a MX Keys keyboard. I need a recommendation for which one. Things I like about Master: Built-in battery. Side scroll. "Seems" comfortable. Free spin scroll. Things I like about M590/720: Easy to access change device button. Cheaper. Nothing too surprising as a mouse. A place hold the unifying rx dongle I am intending to use the mouse to replace M705 with Flow feature but I wouldn't mind trying the nice side scroll on Master. I use my M705 for: Gaming (trackball just doesn't cut it). CAD when my wrist up is up for it (sometimes it's my wrist, somtimes it's my thumb that bothers me). Photoshop/Poster/Presentation preparation (I "twitch" with trackball soemtimes even with high percision mode on). What do you guys think I should get. I really like the idea of side scroll and etc. on the Master 3 but I read it's too heavy for gaming, and M720 seems like a perfect replacement but without the side scroll and I kind of want to switch to non single battery mouse.