It's your job to get rid of algae? I have a magic eraser and a list of tanks for you mister!
I can understand why discusdude reacted the way he did, this post really reads condescending, and I'm trying hard not to imply any tone into it.
Algae eaters are marketed as such, so people buy them to eat algae. I think most, if not nearly every person who gets into this hobby has done this, or at least thought about it.
You are making a big assumption here, that people are buying these fish solely to do a job for them. While it's true that people buy plecos, etc, to eat algae, they also buy them because they like them.
I have a group of otos that I move from tank to tank to eat diatoms, is that an aquarist faux pas as well?
And back to the OP: Yes plecos are poop machines. Another thing you should consider is that sailfin plecos get absolutely huge, so you may want to go with a smaller species, like bristlenose.