Microtechs have a notoriously stiff switch but it's not anything the average user can't get accustomed to over time. Yes, if you hand it to someone that has never fired one before they will likely struggle. Some newer models have Nickle Boron coated internals and while I haven't handled one people say that makes the switch feel smoother and easier to deploy. I've also thought the new-ish Glykon model with switches on the front, side, and back would allow you to "pinch" the front and back ones to deploy which might make things easier.
Guardian Tactical has a unique ball bearing switch and they are far and away the most popular high-end OTF for people who think Microtechs are too hard to fire. I have handled them in knife stores and they definitely take a lot less thumb strength than a Microtech. They're high quality knives but I just don't like the aesthetics as much as Microtech.
Other popular brands are Heretic (owned by Anthony Marfione of Microtech's son), Axial, and Hogue. Kershaw has an OTF on the market that's supposedly pretty nice for the money. I've heard bad things about the SOG Pentagon and would probably avoid it. AKC is another popular budget brand.