It would be nice if we could get everything we wanted in one package; maybe some day we'll just send off a check-list and some one will produce a custom camera for us.
I'll have 4 batteries total for the Sigma and that will have to do. They are quite expensive for what you get, I can buy about ten eBay batteries for the Sony for the cost of 1 Ricoh/Sigma battery. I don't want to invest hundreds of dollars in batteries that I will probably never use again.
But there are other issues too, the RX1 takes remarkably good pictures in a wide range of conditions and it is a delightful camera to shoot. It is much, much better in low light conditions and even when the lightning is optimal for the DP2M, the RX1 has at least more 2 stops better latitude so often even landscapes sometimes turn out better. Also, I prefer the colour pallet that Sony uses over the Sigma colours, especially the greens.
And despite having owned the Sigma for almost a year I am not yet comfortable with the workflow. I often use the Topaz Labs products in my workflow and I've all but given up using them with the Sigma files. I think the Topaz software uses some kind of deconvolution algorithms which produce repeating aliases or "muddy patches" in areas of fine detail on the Sigma Foveon files. But, at the end of the day, sometimes all the ducks line up and the DP2M produces some outstanding images, that's why I will bring it with me.
I have the Sony EVF more or less permanently mounted on the RX1 and I'm able to focus it very easily without having to constantly swap eyeglasses around, which is the case with the Sigma. Some times I have a terrible time trying to focus the Sigma due to age-related nearsightedness.