I have a B393 with in-mast furling. I cruise in the winter (Dec- June) in the Bahamas and have had the boat for eight seasons. The in-mast furling should not be a problem. For a cruiser it's fantastic. I have only jammed it once and it was entirely my fault. After eight seasons I was getting a bit sloppy, furling the sail on any point of sail with a main that was getting a bit baggy after eight seasons.
On a sail from the Exumas to Eulethera I furled the sail while going downwind in fairly gusty conditions. A week later when I was sailing back across Exuma Sound, the sail jammed when I tried to pull it out. It would not come out but I managed to furl the bit I did have out back in. We did that trip on headsail only and the next day I spent two hours un-jamming the sail. It was jammed worse than I thought and, starting at the tack, I pulled it out, bit by bit, as I was hauled up the mast. I was surprised that I had to go right up above the top spreaders before the sail was free.
I learned my lesson and am a lot less cocky when furling the sail now. I make sure there's not a lot of weight on it when furling. In heavy conditions I head up now. The sail will only jam if it hasn't been furled properly.
And I have replaced the baggy main. Got two new sails this season.
By the way, I do have a traditional set-up on my CS36M with all lines leading aft to the cockpit so that reefing is fairly easy. The in-mast furling is a lot easier!!