General perception in this region is that the Sabre and the C&C will be built to a slightly higher standard than the Catalina. The C&C 29 was one of the last C&C models brought to market, hence benefits from things C&C learnt along the way. Personally, I would look for a C&C 30 rather than the 29.
If you are looking for a comfy cruiser that can still sail well - check out the CS30. It rates a bit lower then either of the three you have mentioned - yet has more room inside than the Sabre or the C&C.
CS 30 - Used Sailboat Market in Canada
Find more info on C&C here: C&C Yachts - C&C Photo Album & Resource Center
Including the following:
The C&C 29 foot
The 29 MK I (and the 26) reflected the design thinking of the time which was to take some volume out of the underbody and put it in the topsides thus reducing wetted surface. 29 was distinctly flattened on the bottom adjacent to the keel. This flat was anticipated to provide some lift or planning effect when the boat was sailed relatively flat off the wind, thus further reducing wetted surface. This volume was placed above the water line in rather extreem topsides flair. This produced a "tender" boat at the dock and initially under sail. As the boat healed the flare became imersed and the boat stiffened markedly. The more flair imersed the stiffer it became and it is actually hard to get the the windows of a MK I wet. An additional benefit of this thinking was a very beamy and roomy interior above the water line where the space could be used for living and storage and indeed that part of the concept worked nicely. Unfortunately, as the boat healed and imersed all that topsides flair it started to slow down. The greater the angle of heel the more more the flair was imersed and the slower the boat went. Not literally, but relatively. The imersed flair created increased drag and had the unwanted consequence of providing a large surface for the water flow to tend to push the bow to windward. That combined with the rudder becoming less effective at greater angles of heel and the natural tendancy of a sailboat to round up made the 29 MK I difficult to keep going straight at high angles of heel.
Every 29 MK I owner has had unintentional and undesired round ups into the wind where the combination of the imersed hull shape and rudder made it impossible to prevent unless you had someone very quick on the sheets and sometimes even that didn't help. Holding the 29 off the wind at high angles of heel requires excessive rudder and that adds dramatically to drag. That is up to the point where the rudder stalls and you round up quickly. Sometimes so quickly, the boat will actually tack itself and that can create some very hairy situations on the race course. This design thinking was pretty short lived with 29 and 26 being the prime examples. They were getting pretty far away from it with 34 . Obviously, this design thinking wasn't the best idea C&C ever came up with. About the only solution is to sail the boat relatively flat (15 to 17 degrees) and keep that flair from imersing very far, much like you would sail a dingy. People racing MK I's will ease the traveller down, carry a luff in the main and when it really blows may carry the main almost fully aback while driving the boat on the jib. Sometimes you even have to feather the jib to keep it on its feet. Whatever it takes to keep the boat upright. Don't misunderstand, you can drive a MK I with the rail in the water and its as much fun as sailing any other C&C that way. You just have to accept the fact that the 29 next to you that's at 15 degrees with the main luffing is going to kick your tail.
While 29 was a great sales success for C&C with many one design fleets (some still going today) and is a pretty good looking boat, it left a lot to be desired from a design standpoint. It was one of Cuthbertson's least favorite designs. As racer / cruisers are not generally intended to be sailed like dingys and for the undesirable traits this design produced, the thinking was abandoned with only 29 MK I and 26 truly exhibiting that philosophy. 29 MK II, as I think we all know, is a toally different boat from a different time and the two designs share absolutely nothing in common except their name. The heel figures quoted for the MK II I would suspect are quite accurate.
Actually there is a lot good to say about the boat. The 29 MK I is a great light air boat both up and off the wind and a pretty good medium air boat. The cockpit is roomy and comfortable (with cushions) The decks are easy to get around. Because you should sail it flat, its pretty dry in a seaway. The cabin is huge for a 30 footer with lots of storage. You can feed or entertain 6 easlily in the saloon. You can drive it with one finger. Upwind in light to medium air it is so well balanced that you can set the brake and it will sail itself for 10 or 15 minutes. Beauty is in the eye of the beholder, but I think its a good looking boat with a pretty sheer line. It handles well under power and backs down nicely - even with a Martec. The galley is compact and well laid out. The boom is high enough so most don't hit their heads.
And, of course, its a C&C.