The shower head is a little weak. I have one. It works "ok". gotta hang it at a minimum of a foot above your head for best results. The hose is a little floppy. If you spend a few minutes more setting it up its definitely a lot better. The good part: Put on your dash and it gets nice and hot. Its flat shape is good enough where it doesn't roll around. *unless you fill it to capacity!*
I ussed to use a seattle sports shower, and it folds down super small. The MSR was a compromise- one hydration pack/shower unit. A little annoying though, as trying to pour hot water in is a bit of a drag. the seattle sports has a open top like a dry bag- lets you dunk. Im a little bit of a parasitic phobe, so I treat all my water- regardless if its being used for shower or dish washing. I use the MSR Miox and make my chlorine dioxide brew. Toss it in, and wait, setup camp. Conversely, if I have several people, I'll bring my katadyn base camp, fill that, and let it fill up the bags.
If Im car camping, I've since upgraded to the Nemo pressure shower. (helios?) . Its really a whole heck of a lot better in a lot of regards. Its on the ground for one thing, so you don't need a place to hold 6+ liters of water overhead. (or 10, depending on the size of your water bag). That makes life easy. The small hole on top is annoying, so bring a funnel. The issue is I like to shower at night, so for day 1, I need to heat up water. Day 2, generally not, as long as I didn't move around that day. In the summer, I can keep it in the trunk, filled with water (but not pressurized) and it will also heat up after the day.
The funny thing is, the Nemo takes up the most space (which isn't very much) of all the other items combined. Msr 6L bag, the seattle sports, the Miox, the Katadyn base camp... all of it fits in a large shoe box. I like the flexibility of being able to scoot off for an overnight from base camp (or vehicle) and still have a shower.
