Laser is error prone, unless you get a good one. The inner workings of the Chinese units sold by most telescope shops are rather poor quality, and difficult to collimate because of the flimsy construction. The housing is good, but the way the laser is mounted and the laser itself are not. If you get a laser, get a good one.
Cheshire works well but when collimating by yourself it can be a pain to go back and forth between collimation screws and focuser of a large scope and trying to remember which screw moves the mirror which way. A good laser with a viewing window would help there, and you can always do a final check with the cheshire and an even more final check with star test.
