While I'm not entirely pleased with the product as it currently stands, I wouldn't ask for a refund. The game, as a modding platform, is fantastic, and within a few months I think the modders here in the Subsim community will make it a truly remarkable piece of software. All of the game engine components that made SH3 and SH4 so great are still in there, they just need to be re-enabled.
And, personally, I've had one of my best Silent Hunter moments of all time with SH5 (although it was probably caused by that damn morale bug

): Yesterday I torpedoed a lone merchant at night not far to the south of Ireland. The ship was sinking slowly, so I decided to wait around for awhile until it finally slipped beneath the waves so I could get credit for my sinking.
Suddenly, a shell whizzed overhead and a huge geyser of water erupted next to the conning tower of my sub. Apparently, the ship had radioed my position and 2 destroyers were bearing down on me at flank speed, guns blazing. I, or my crew, didn't see them because it was so dark.
Anyhow, it was ridiculously satisfying to run down the ladder, jamming the "crash dive" button, while the sea was churned up by a volley of 5" shells.
Just think like a postage stamp---stick with it.