Chris, I have played Mach Dunes and was incredibly disappointed. The greens were 'carnival-like' and the condition was awful. I realise they were hampered by the whims of the "bug and insect people" with what land they could use and what needed to remain untouched, and I feel for the developer. I spoke with Kidd's Project Manager at the time and suggested he visit some classic courses to see how great greens are built. Machrihanish does no fit this category, IMO.
The accommodation was not open at the time I visited, but nearing completion and looked to be very good compared to anything in the village or in Campbeltown, so that's a big tick for them.
The price they're offering (179 GBP) is competitive with the three rounds at Machrihanish GC, plus B&B Accom in the village and I'd suggest that to any friend who were going there rather than subjecting them to Kidd's folly. I'm no fan of the greens at the Castle course in St Andrews either, so that may give you some idea of where my preferences lie.
John