It depends..............
If it is simply a rearing tank for the fry, and you have adequate feeding for them, I find plants get in the way when trying to do water changes and such.
But if you want to place the female in a tank, have her drop and then remove her later, plants are great to give the fry a place to hide. Also, if you dont have the ability to feed as often as you'd like, the micro organisms that live in the plants are great for your baby fry. Plants also provide additional filtration for the tanks in cases when you cant change the water very often.
Really, its just a preference thing IMO.