That's a tough question. I don't think the C36 MKII has any inherent flaws above and beyond any other sailboats. Yes, some report chainplate leaks, "Catalina smile" at the forward hull/keel joint, leaking openning port gaskets, stress crazing areas- but these seem to be the norm with any older sailboat and make. Any brand engine can have "warts" too. The Universal M35 Universal (on newer C36's) is a Kubota with marine modifications and is a very good engine. The OEM build had a Sherwood raw water pump, which many owners have replaced with Oberdorfer for ease of impellor change. The shaft that drives the pump impellor has a rare tendency to fail- which can be an expensive fix. Universal offered a recall/fix- simple installation of a bearing sleeve which can be performed when the water pump is removed. Some have reported failures with the fix in place. From reading this web site- I would guess a failuer rate of maybe 3-5 reported over 2600 +/- boats, so it shouldn't be a concern. The transmissions tend to be noisier than most of us would like. The OEM anchor well thru-hull is at the waterline and made from Nylon- so it deteriorates from UV. Replacement is recomended. 

This web site is an incredable asset for C36 owners- all kinds of mod suggestions, help with repairing things etc.

We've owned a 2005 for the past 4 years and couldn't be happier. We had a C30 prior. The C36 ease of boarding, added room/storage, in-mast furling (providing furling safety from the cockpit), and great engine access,  were major improvements over the C30 for our family crusing goals. It's a wonderful, boat.

I am very happy with my 1999 C36 fin keel. I spent one year looking for one. It seems that after 1999, due to downturn of the economy, Catalina produced affordable versions. That is they cut back on features that was standard on their basic model. You may consider the standard rig rather than tall rig as C36 gets its power from the jib and I use 110% and it is more that what is needed. Of course I am in San Francisco Bay with strong winds in the summer.
Take your time, do not rush.

Great boat.  I have 98 tall rig wing keel in New England.  If I had to do over I would get fin keel an additional foot of draft shouldn't curtail the cruising grounds too much and I would feel more comfortable around lobster pots and potential groundings.  Wing keel exposes the rudder to grounding impacts since both are at about the same depth on wing keel boats.

We've been very happy for the past year with our 1999 C36 tall rig, fin keel.  As you will read here, the boat is a great couples cruiser, and can be easily single-handed with an autopilot.  As with any 15+ year old boat, the individual boat and maintenance is the defining feature. There's nothing particularly troublesome or weak on this vessel that's caused it to wear badly.  Some of the things that I have read, but not experienced, are leaky chain plates, fallen keel (Catalina smile), and backed up head vents.  

Some design elements that you may want to change: The holding tank vent through the port stanchion (a Catalina exclusive) is a silly design that just plugs up eventually.  I replaced mine with a mushroom through-hull below the rub-rail, re-routed the vent hose, and filled the deck hole.  The jam cleats for the main sheet are a pain as the line keeps popping out when not on the cabin winch, and I don't see it as a real safety factor.  I'll probably replace mine with normal clutches.  Mine had under-deck autopilot, so I don't complain about the wheel autopilot that some have problems with.  My bilge is leaky (somewhere) despite having a PSS dripless. That's a problem for another day. The holding tank is only about 14 gallons, so limiting if you can't pump out or dump frequently.  The other tankage is more than enough. The boat is roomy enough that you can access and work on most problems without being a contortionist.

As noted, the extra 18 inches of depth may affect some anchorage selection, but not really your cruising grounds.  Who is going to sail over an 8-foot rock saying, "it's ok because I only draw 4.5 feet"?  

Go buy a good, surveyed boat and join the party!

Keep going, Phoenix. It's a buyer's market in larger sailboats.  If that person wasn't ready to sell now, there are a dozen more C36's out there with motivated sellers. This is one of the largest production runs in history.  Also, it costs most of us a couple thousand dollars annually to keep, insure, and store the boat, even if not used.  Let us know when you 'join the club'.

I think the best thing you can do is to get as much info as possible on the boat history. Invoices from boat yards, internet searches on the current and previous owners, conversations with others who may know details about the vessel. Feel free to email me at stevesteakley@sbcglobal.net if you need further tips on the process to have a complete boat history in your hands before making an offer.