When I was doing paper logbooks, I logged daily totals for 121.

When I switched to electronic, I was able to import data from my company's software, which was of course by leg so I switched back to leg-by-leg.

I doubt anybody cares too much either way, but I would recommend an electronic logbook...simplifies massive 121 data entry and helps catch errors. Also the filters greatly simplifies filling out complex airline applications. If you end applying to majors after ten years at a regional , you'll really want electronic. The sooner you switch, the easier it will be to do the data entry.