I need some advice about deveoping sheet film.

When I develop in trays, the development is very uneven, making me think that even my best agitation efforts come up short.

A Yankee Agitank is a little easier to use, but still gives me uneven negs.

Have any of you used the tubes that J&C sells? I also have access to a Besler Color (made for prints, but I'd try it for film if its not a horrid idea) roller tank thingy.

Any advice would be greatly appreciated.