OP, speak to someone at BA to double-check you can indeed do this as outlined, bearing in mind what others have said on this thread.
However, if you can, it is absolutely without a shadow of a doubt doing this for £75 more. Regardless of whether you take a day or night flight - even if just sleeping the F 'suite' is more spacious and comfortable for sleeping, and the mattress topper and quilt make a difference to sleep comfort too.