I've owned most of these in my Pilot, they are hit-and-miss but here is some fit-to-car info: (It's a 2006, so LATCH only second row outboard.) Graco Mysize - had this (I think it was a Size4Me, doesn't really matter though) installed second row passenger side. It was short on legroom and I didn't love the install UNTIL I reclined the second row seatback a single click - it seemed to nest the S4M right in there, I loved the install and much better on legroom. I was using it for a 40" 4yo, before they made some changes (new buckle, removed 40" restriction, allowed outer crotch strap usage) so I didn't love it, but for a new baby, it would probably be great. I also have photos of it in the third row, so it must have installed okay back there - I am guessing the second row had to be moved all the way up. Combi Coccoro - I had a really difficult time with this seat in the Pilot. It was a great outboard install, but where I needed it was in a center seat, and it felt like I was consistently reinstalling to get a tight install. YMMV. It did fit in the third row with the second row NOT quite all the way up, which is the only seat that did that for me. I just could never get a great install due to FOTB seatbelts and long buckle stalks. Installed with LATCH might make it a whole new bird though. Britax Marathon - I am guessing you mean the MA70? I had a RA50 (so classic Marathon shell) and ended up moving kiddo out of it - I think I am just not a huge Britax lover. I turned an older kiddo FFing to move the RA50 kiddo into her seat, but then again, the RA50 kiddo was 3.5 so lack of leg room was to be expected! He was fine comfort-wise, I was just struggling to buckle around the legs. But the install was fine, I think I only had him second row driver. Chicco Nextfit - love love LOVE the NextFit RFing LATCH install. I am not much of a LATCH user, but I haven't even tried the seatbelt install, outside of our test bench. It installs in a reasonbly compact manner. I haven't tried it in the 3rd row, but if it fits back there you'll need it upright as possible with the second row slid all of the way forward. It's bulky but I can seriously install the seat RF or FF in no time flat, so for me I would consider it easy to move around. I really like the space age/Euro design of the seat, but I think that's a personal preference thing, and it doesn't seem any huger than any other large convertible seat to me. Obviously those are all just my opinions but thought it might help to have some input in the same vehicle
