I have travelled lately with two types of kits, one an M8 kit similar to yours except I end with a 90mm TE and combine my 50 and 35mm into a 40mm Nokton. While it is compact, it is NOT necessarily light. The other is a Canon dslr, last year it was an XTi, and two zooms and fish. Went to Paris with the latter and G7 in July, was great, light and made some great images...More recently, a 5D, 24-105, 70-300USM IS, 20mm, G9. All worked great, and depending on mood, performed the job. In some ways almost an embarassment of riches...a FF XTI would be grear for some trips but not others, say Africa, where the 1.6x would be handy..
Guess one needs different tools for everything, selecting what is taken is the BIG question always...what body, what lenses??? There is not a perfect camera or lens. For me, after a half dozen P&Ss, I am done, just does not work for me, except for handing a stranger a camera for a snap, just too much loss of image quality. Guess then, it might be a XTi or XSi as backup, can always put it is P mode for snaps....but that means carrying carrying two cameras always, and at all times if I want to have my "GOOD" camera with me two...
Maybe in a year or two when base dslrs are 14-16mp too, I can do it all with one camera, or at least feel comfortable enough to go with just the XSi type camera alone. If I could just limit my end use to just personal photobooks, the XTi or XSi would do it even now, but alas I also like to have the option of doing 24x36 prints or bigger ......guess I don't have to look that closely at the prints.....
guess the end question would be two small body dslrs like the XTi size, one FF and one 1.6X...but with a 511 battery, then you could really two body, two lens kit and cover most everything so I guess, after my long winded thinking, I would like aXSi with a FF chip for travel, can I also request a 40d size body with Mrk III speed...