I used a 90mm and the WLF. One back because the only other one that I have is the 220 and I had everything plus the light meter, 35mm body (with a 50 mm lens) all stuffed in a camera bag that wasn't designed for MF. It was a good experience for me to have to reload the back in a hurry.
Learning how to quick-load is a very good skill to have! Post some images when you can; I would love to see what you did! Were you shooting B/W?
I find that the RZ handles just fine hand held. I don't know why people complain so much about it. They make straps for a reason. It has fast shutter speeds for a reason. They made the 110 mm f/2.8 lens for a reason. (The 65mm f/4.0 works great hand held as well). They make fast films for a reason. They make prisms and winders, and all that jazz for a reason (though I usually don't use either; sometimes a borrowed prism). If light is strong, you don't even need fast films. I shoot 100 films with my RZ frequently hand held.
Now, will results be better on a technical level with a tripod? Of course...but that goes for ANY camera. Hand holding the RZ, you get a versatile and stable system SLR platform that will allow you to get fat film frames that you would not be able to get on a tripod. (Otherwise, you'd be using a tripod, right?) If you want to hand hold for 6x7 negs, it is certainly a perfectly fine choice, if not an excellent one. Because it is an SLR, it is certainly faster and more accurate in quick focusing situations than a rangefinder, and because of the design, doesn't shake as much as a Pentax 67 IME (plus it takes backs, which you can preload, allowing you to change to a new roll of film in about 10-12 seconds).
"Truth and love are my law and worship. Form and conscience are my manifestation and guide. Nature and peace are my shelter and companions. Order is my attitude. Beauty and perfection are my attack."
With regards to pics. I also hope I got some good ones. No guarantee that there will be any interesting pics but hopefully the exposure and composition was on. I get great studio results with the RZ67 but for street photography there’s room for improvement. I metered once and then as the light changed I changed my settings by guessing. I don’t have too much experience with using the light meter outdoors where the light is changing (sun setting) and was trying to avoid metering the scene every five minutes. I hope it worked. At any rate, it’s exciting. I hope to be able to use this camera for the next 20 years or more.
I used my RZ67 with the 110/2.8 as a walkabout camera for about 6 months. I really like the 6*7 format, since I love 8*10s and it is so easy to get a great negative out of the system. The weight isn't really a problem, but my RZ has a habit of pocking in your leg when you carry it. Same with other Mamiya cameras, my C3 does the same. Sharp edged cameras Mamiyas.
More recently i've gone back to my Hasselblad for walkabout duties, but it managed to jam last week when I was away (did stick half a dozen films through it first so it wasn't a disaster). Whilst it's getting repaired and serviced i'll take the RZ out for a bit and see how I go.
I have to say, for 6x7 walkabout, I still think that the Mamiya 7 is tops, with either the 80 or the 65. I don't have one (too expensive), and I love my faithful old RZ, but I have borrowed a 7 several times and as an old rangefinder shooter, I think it's the best. But that's just me.