It depends on what you are doing: For live sound, built-in effects save you having to patch in external units. Easier to carry around, set-up and tear-down.
If you want to record with your mixer, even the simplest recording software has a whole host of effects that you can apply after the fact and tweak to your heart's content until mixdown. "Printing effects to tape" is a bad idea unless you really know what you are doing. So if you want to record rather put the extra money into a mixer with a better sound quality .
Tailon. wrote:
where can we get the alesis mixers
I'm not sure who the distributors are at the moment.