I'll be embarking on a 6 week trip to Europe at the end of this week. 4 of those weeks will be vacation, so I'll have as much time for making photos as my wife will endure (and she's remarkably patient as long as she has our 20D in hand). We'll spend a good while in Italy, some time in France, Germany, Switzerland, Austria, Spain, the UK, Belgium, and perhaps Norway.

We'll be travelling as much by plane and train as possible, and won't often have access to cars. As a result, we're trying to stay trim with our luggage, and consequently my gear. She'll have the D-SLR and a few lenses, and I'm definitely bringing my Mamiya 6 and lenses. My tripod - a Bogen 3021 - unfortunately takes up a lot of room and a has a goodly heft to it, but it's the smallest one I have, so it's coming with me.

I like shooting 4x5 and making big enlargements, so I know I'll miss it no matter what - especially since I imagine many of my photos will be architectural photos. That said, I know most of the places we'll be in Europe are mich more crowded than the places I normally photograph (landscapes, etc), so I'm sure shooting with the Mamiya 6 will be much nicer at times.

If I bring the 4x5, the kit will consist of a Tachihara camera, a 75/4.5 Grandagon, 121/8 Super Angulon (I could substitute a 100mm WF Ektar that has some fungus and scratches to save some weight and space), and a 210/5.6 Fujinon W. I shoot with Grafmatics, so the weight of the LF kit alone should be right around 15 lbs.

Many days we'll be carting all of our luggage with us on trains, buses, and on foot for a significant portion of the day as we travel between locations and seek lodging for the night.

My questions:
1) How much will I kick myself if I leave my LF gear at home?
2) How often will I feel comfortable setting up my LF camera for a shot?
3) For church, castle, and other building interiors, how accepted is it to set up for tripod photos?
4) Any chance if I leave my LF camera behind, I'd be able to get away with just a monopod for my Mamiya 6?

I'd appreciate any insight anyone has. I need to make a decision by Friday.

Thanks for putting up with the long post.
- Jon