Reservior vs No-Res type Master cylinders?

Hi all-
I just put in my brake pedals today, and in studying the plans see that a firewall reservoir is used (RV4). I have a Grumman Yankee that uses non-reservoir MCs on the pax side and reservoir-type MCs on the PIC side. I'm curious why the RV4 uses a separate reservoir. Is it simply for maintenance/safety issues - easy to fill, easy to check? Do side-by-side RVs also use a reservoir, or are they similar to the Grumman? My curiosity has been piqued...
Eric

The side by side RV also use a single reservoir on the firewall. Once the panel is in place, having your head by the pedals is not a fun place to be. I wouldn't want to get down there every time I check the fluid level.

However, some people have placed resevoirs directly onto the master cyclinder (writeup somewhere) so that you don't have to pull off the cowl to check fluid. This also elimites the low pressure side of the system, which was a huge nuisance and leaked frequently for me. I've got an iphone pic of mine. Also I always bleed from the bottom up so if I add fluid I won't be pouring any in down there anyway.

I put reservoirs on master cylinders. Working good. I wish they were transparent.