I have been to two maid cafes. One in Akihabara and one in Sendai, Miyagi Prefecture. Akihabara is the otaku center of the world, so some but not all the cafes have become quite commercialized. I found both experiences fun but got much more personal attention and an enjoyable experience in the smaller cafe in Sendai. Maids will talk with you briefly and cast a magic spell over your food which will make it even tastier!! Often pictures are not allowed at these places, unless you pay 500 yen or so to take one with one of the maids.
I find maid cafes pricey, but fun for something different and unique to Japan. In Akihabara the maids advertise on the street then will guide you to their cafe which is usually tucked inside a building or alley. The first maid I asked was actually not part of a cafe but a maid massage service! So my advice would be do check out a maid cafe, but be careful your budget or getting more than you bargained for!