I've started switching to it last week. Previously my setup was almost the same, but I didn't have my heels on the ground which caused some "butt lifting" on top sets. Now that I'm not lifting my butt by bench is about 2.5kg lower (haven't really pushed it all the way yet, but judging by how high I got and how it felt), which was to be expected.
Which part of it feels weird? For me it's the "sort of push press but not", still getting used to it.