The trouble with large format that is quite noticeable is it's the first format to receive the chop in availability of films; it's an ongoing annoyance that affects all formats, but 4x5 is not particularly well catered for despite obvious enthusiasm for and dedication to it in art, studio and landscape photography (in many disciplines replaced by digital, which I feel is inferior and insulting to the art form, not that we can do much about it, even as a vociferous minority). It is a testing format to use that requires time, patience and a methodical, measured approach, with a good deal of metering nouse about you (without that singularly important aspect LF is not the choice; learn advanced metering with a manual camera and move up and up as skills and the amount of time you wish to devote to it increase). All things else being equal, you must be hellbent on producing the very best images you can from the oeuvre you have specialised in (this holds though for a lot of serious, studious photography in any format from 35mm right up to ULF and beyond). It is observed that it will be the first format to disappear, quicker than MF, 35mm and even ULF because there is not a big nor growing market to sustain it; creative peeps take LF papers and chop them down to 4x5 size, and a great many are in the B&W league, where LF had its foundations more than a century ago. The important thing here is to get your hands on whatever you are comfortable and competent with and go out there and shoot film like there's no tomorrow!