I light mine with a weed burner... It only takes about 30 seconds or so, but I actually watch my pit thermometer and and usually take it off around 200 degrees.
I bought my weed burner to light my UDS. I just get a spot in the middle lit which only takes 30 seconds or so as stated above. You can easily see what is going on down in there. Works great.
Sometimes I do. Just depends on what all I have going on. It works great esp. if I need the pit up and running quickly, but if I have a little time I'll just use the chimney to get started. I don't use it all the time because I have the torch removed from the propane bottle and stored up high (father of 8 & 10 year old boys mod) and I'm too lazy to get it down sometimes.