How useful is it to play chess against the computer to improve?

chessbased

I think they are helpful.I learned the move-order of troublesome advanced french from computer play(Tarrasch Gui with oepning books).

Smositional

What I like to do is to set up a smosition that is advantageous for me (not a material advantage but a smositional one). Then I play against the engine and try to convert my advantage.