Pan F has a very difficult time with the extremes of open lighting in the desert. You won't get much shadow differentiation. I'd assume your old
Pan X would have the same problem. TMY400 will give better edge acutance than TMX100, but both have excellent gradation unless you
overexpose them and blow out the highlight. Acros works nicely is you give a little extra exposure for the shadows. By Blackrock Desert, I'm
making the assumption that some black rocks might be in the venue! I think you'll regret it if you leave your 4x5 behind. Having plane of focus
control and the extra capacity for detail under that sharp lighting is important. The windiest conditions are in Spring anyway. Just keep everything well wrapped. Small cameras aren't immune from dust either; but you might want one along as a backup system.