I find it is the one sporting event that matches, or often exceeds, a good test match for managing to be hypnotically interesting, and yet also ok if you have to get up and go have a meal and come back, and be able to pick up what's gone on very quickly.
Tbf however, I didn't really get it at all until I worked with a guy who was fanatical and would talk me through what had happened the night before and give me hints as to what to watch for the next night. Since then, even with the spectre that whoever your watching being amazing is doing so on roids, it's absorbing stuff.
For me, has the same scope for epically heroic cameos by anyone at anytime that cricket does, even if at times the main result is not really in doubt.
Having Cadel Evans as a seemingly genuinely clean (although unfortunately, I don't think anyone can afford to be completely sure about this in cycling) competitor who is both Aussie and seemingly perpetually battling with insane bravery one-out against better staffed teams certainly has added to the interest for me in the last few years.
Will probably record both, and flick back and forth live.