I also wasn't crazy about Primehouse. A $45 aged sirloin I had there was not as flavorfull as I would have expected and was cooked more medium than the requested medium rare. At those prices I am not so forgiving.
BLT Prime...no comparison. Superior on every level, as you can see from the other posts. The only real positive on Primehouse (in my book) are the spared-no-expense bar stools in the bar/lounge. Might be the most comfortable in the city.