Symphony 4 is a winner. The more I hear it, the more I like this work. Second movement is great. In fact, roll over, Beethoven.
Did you see what I did, there? The long winter nights just fly by in our house. Oh, yes.
The andante shows Simpson can write tuneful sections when he chooses, and I would probably recommend #4 as one of several starting points for those new to his music. Having said that I would also come at him through #8 or #9, if you enjoy big, bold works.