I bought my first multitool in 1993 - a Gerber Multiplier. It was an ok tool, as long as you somehow managed to not pinch the crap out of your hand when using the pliers. in 1995, i was gifted a classic Leatherman PST. This tool replaced the Gerber, and accompanied me on all my outdoor adventures until I got a 1st gen Wave in 1998. The wave was a great tool, but it was still relegated to camping/outdoor duties. My trusty SAK Tinker or Hiker remained my constant daily companions.
Somewhere around 2002-2003, I acquired a Charge XTi that came with a pocket clip. This spelled the demised for the daily carrying of an SAK. Since then, I have always had a Leatherman tool on my person whenever I have left the house.
I had the pleasure of working for a Leatherman dealer for a few years, and was lucky to try out a variety of their models. The Charge XTi and the 2nd gen Wave have been my most carried. The Surge is nice, but it is on the large and heavy side, maiking it cumbersome for pocket carry (for me, anyways). The Crunch is great for the Vise-Grip-type feature, but I think its utility is hampered by the other implements it has; or doesn't have. The Juice series, is nice because they are small, but their size is also a drawback IMO. The major blades/implemets and the pliers are smallish and limiting. However, the Juice scissors and corkscrew with assist feature work well. I feel the various Juice flavors are best suited for a mini kit, or some other occasional use application. For the last year or so, I've been commuting with a Skeletool. It has proven to be an excellent EDC piece, with its knife blade, pliers, and multi-bit screwdriver all seeing about equal use.
The only other multitool I have in my stable is an original SwissTool. It is nice, but it has been overshadowed by the newer, slicker Leatherman tools. I believe the SwissTool rides in the glove compartment of my wife's car these days.
I have never been bothered by the ergonomics of the multitool pliers. They have all worked well enough for me. The original PST wasn't the most comfortable pliers to use, but when Leatherman began rounding their handles, it was as if a giant sigh of relief was emitted by hands everywhere.
Finally, remember what it is: it is a multi tool. It will perform a variety of tasks, but it most likely won't out-perform a purpose-built tool. It may not cut or carve as well as a good knife, it may not , uh... plier as well as a real pliers, It may not open cans as well as a turn-key can opener, it may not be as comfy or easy to use as an actual screwdriver, you won't be sawing down many trees with the saw, and the scissors may leave you with carpal tunnel syndrome after cutting out an article from the newspaper. But, you can do all this stuff with one tool (except maybe for the cutting down a tree part). The pocket multitool is like the WSK of pocket knives - Some may see it as gimmicky and unnecessary, other may see it as entirely useful.