I'm a bit late to the party on this one, but for at least the last 5 years I've used rechargeable clippers to trim everything. Beard, hair, face, .... yup, everything. Prior to that I wasn't a fan of shaving due to irritation and annoyance, so I would get pretty scruffy looking between shaves anyway. Now it's quick and easy to run the clippers over my head, beard, and mustache at a longer setting, and the rest at the shortest setting. I end up sporting a perpetual "five o'clock shadow" but it suits me and gives me that "don't f___ with me" look that tends to discourage trouble.
I invested in a higher quality model that I expected to last, and it has done very well so far: Conair HC1100. It's not even that expensive. Around here the cost of about 4 hair cuts is the break even point.
Hair maintenance is SO much easier when it's less than 1/4" all over. It might just be the best choice I ever made. I did need to invest in some hats though to avoid sunburn and cold.