What can I say about DD's carseat is that
I LOVE IT!
It takes about 8-10 minutes to install tightly in a new car with a learning curve of how the MC fits into that specific car (angle, snugging down, figety bits I do). Then after that first time, it takes maybe a minute or two to install it again.
BUT it must have a 3 pt seatbelt harness to install correctly!
NO LAPBELTS!
I've had it in Passats, a friend's Volvo SUV, mercedes, Chrysler minivan, vw rabbit/golf, Toyota Camry -- so far, I haven't found a car it won't install into yet.
Mine is an XP version -- which has a lever along the bottom that, after securing the car's seatbelt, it presses down and additionally tightens the belt. The regular version doesn't have that option. I don't know how well that works at all. Both have clips.
To install -- Basically, you recline the seat, swing the lever on the bottom platform across, thread the seatbelt through (making sure its in the proper spots), snug down the shoulder harness & clamp it down, then pull the lever back into place, de-recline it, et, voila, all done. The first time in a particular car, I'll go back after I move the seat around and pull out any hint of slack before engaging the lever again. The 2nd time usually makes it rock solid in the car.
DD's always been comfortable after hours in the seat.... longest trip was about 12 hours with only a few breaks and she was pretty sick to begin with, so her fussy level was quite high. Still, she did very well. I like that I can reach back while I drive and easily recline her when she's sleeping.
I've only adjusted the shoulder harness once and it wasn't any big deal. The cover is easy to remove since the entire area around the slots & back is attached by velcro. I've washed it once -- rest of the time crumbs were brushed out. The shoulder pads are sewn down, but I think they'd slide off if you detach the harness at the base. They're kind of a soft velor on the top, but a smooth grippy material on the bottom (I know, it doesn't make sense, but they don't slide around or interfere with tightening). To tighten -- pull on the bottom strap. Loosening just takes a push above where that bottom strap emerges.
It's not that heavy to carry, just bulky. Maybe about 22lbs or so.
Oh, and one of the points that I loved after dealing with the Triumph -- all belts have fastening points so when you put your child in there, they don't get in the way! It doesn't matter now, but dd would FREAK out if the buckle was under her when she got into her seat
We've had the seat now for about 2 years and if DD wasn't at the top of the growth charts, I'd easily see her in it for another 18 months. She's a hair over 1/2" under the top slots.
I checked to see if the manuals were still online to see, but apparently everything is now video demo.
http://instructions.maxi-cosi.com/index.html
If you want to see pictures, just pm me with your email address and I"ll send some. I can't seem to post images directly, nor are they great examples of tight harnesses since we were usually at a pit stop or resting.
HTH with what you want to know