Up until a few years ago, we used Mears all the time too. The majority of the time, the process was fairly smooth. But if you arrive at a particularly popular time, the crowds can be daunting. What is interesting is that if you arrive at an "off" hour - say about 10:00 p.m. - there are not many vans around and you may still have to wait for one to complete a prior run. In effect, you are waiting longer because less vans are in service.
But if your Mears experience is not pleasant, you do begin thinking about other options. For us that was a towncar service. For others, that many mean car rentals. In my opinion, the way the vans are loaded needs to be examined. It is not fun crawling over other adults to find your way back into the nether regions of the van. For people of size or those with physical challenges (not wheelchairs) it is a gymnastic feat. And then crawling your way back out again
.not fun. And once another traveler took my bag, thking it was his. When the stop was made at my airport terminal, it was discovered that his bag had been left behind and he had mine. Luckily, the driver was able to sprint back out of the airport, back in again and catch the guy. I dont blame anyone for that one so many black suitcases out there! but at least now I dont have that worry.
It may be that I just feel I need more creature comforts and am willing to pay for them. I can't say I ever looked forward to using Mears, but I didn't hate it. I'm a fairly flexible individual. But I think starting out a trip on the right foot is important and Mears was just becoming too much of a hassle for us.