Just got some shimano DX caged spd pedals and looking for a good shoe recommendation. I want to be able to unclip at the top of the hill and ride down unclipped when the trail gets nasty. Will I get good grip with the right shoe or will grip always be a problem when there's a cleat on the bottom of the shoe? Right now I have a XC racing type of shoe and it slides around way too much on the pedals to ride downhill unclipped.

how about the matching shimano DX shoe?

"I want to be able to unclip at the top of the hill and ride down unclipped when the trail gets nasty"

Why?
You'll have far less grip than using flat pedals unclipped
If you aren't confident with SPDs either make yourself learn to get used to them (use them more where you don't feel comfortable, build up gradually) or use flat pedals instead?

Back to your question, do you want to do any walking in sloppy conditions at all? Something like a DX shoe (or for eg the Vans SPD shoes) have more of a waffle sole, that will clog more easily than something like a knobbly treaded Specialized Tahoe or Shimano MT series shoe

You want these, proper storm trooper shoes and guranteed to make everyone you ride with rip the p!$$, nice shoes though I love mine.

specialized buzzsaw if you can still get them