ah not bad. better than i can do. im still workin on the backsides. hopin to move to frontsides soon.
Aside from the whole spinning part the 270 on feels more natural than just a regular FS I think because you don't have to counter-rotate your upper body - when you do the front 270 spin it puts your upper body in the right position for fs boardslide. Weird, I was kinda surprised at how easy it felt compared to just a regular fs.
When you say backside I think you mean fs lipside - a true backside would be approaching with the rail/box to your heelside. The terminology is weird it still confuses me but basically fs/bs refer to your position relative to the feature. Then, boardslide is if you bring the nose over the feature first, lipslide if you lead with the tail. So a fs lipslide and a bs boardslide look almost the same except for the approach.