The CCR is a description of the rig -- Cruising Control Rig. It is an aft cockpit boat that is distinguished from the earlier 3700's by a dual furler
headsail setup with a smaller jib
and a reaching headsail. I believe most also came with a roller furling
There were some issues with some of the '00 series Tartans prior to a company ownership
transition. If the boat you're looking at is a 2011, those issues were, I believe, resolved. That said, you'll want a surveyor
who knows the more recent Tartans to look it over carefully.
We've sailed on a friend's 4100 and I've crewed offshore
on a 4600. Those are all Tim Jackett designs that differ from the 3700 mostly in size, but none had the CCR rig. They sail well in a broad range of conditions. I will admit to lusting after the 4100 until we got our boat.