I think you will be perfectly fine. Our master bathroom is extreamly tiny (7' x 7.5') and believe it or not we expanded our shower to ~36" x 45" frameless glass shower (was previously a tiny 32x32 shower enclosure).

We did full glass and a large recessed niche...which really opens up the space. We love it!

I really don't see 36" x 50" being an issue unless you are abnormally tall or big people :-)

http://ths.gardenweb.com/forums/load/bath/msg0318035216653.html

Thanks for sharing the photos of your remodel. It does look beautiful. Good to know you love it so much. Sometimes photos can be deceiving, but it seems like the experience you've had with a shower this size is excellent... That's great news for us.

As for our heights, no giants here. I'm 5'5", the hubby is 6'1".

We're very pleased with 3' x 4'. 5.5 and 6 feet tall. The hot water warms it up quickly, and there is plenty of room to move around w/o bumping into walls. Put a ceiling light over it to keep it light and bright and enjoy.

-Babka

I have a 3x5' Kohler cast iron shower pan and could have easily went with 3x4' in hind site. My shower is in an alcove with only a glass door front. There is plenty of light through the door and I have a ceiling light in the shower with my exhaust fan. Even if I had gone with 3x4' there would have been plenty of light. Like Babka suggest put a light in the shower. The shower still needs the rail to mount the handheld, and the grab bar under the nook installed.

I have to point out that I did the tile job myself and you can see the lipage I have with those large tiles. If you are DIYing the tile, this may be a problem if you use large tiles. I was able to get them very level and the walls plumb but I could not prevent the lipage :/