Why is mp recovery useless?

I still love my oak barrel. Before pirates came out in gMS, the guides always followed as getting max MP recovery and 1 oak barrel.
But seeing it now, I don't really think it can beat barrel. It's a good skill I admit, but I do prefer barrel a lot more and I use it very often when traveling to far distances especially that map before the CWK jump quest.
I have my 1 MP recover on "-" key and I actually do forget that I have the skill sometimes :[