The BF and I went in 2006. I did not race due to the fact that I ruptured my L5-S1 disc 3 weeks before the event, and was sidelined for the next 4 months, but we did check out the course on a scooter 2 days before so I got to see it. I did do the swim, then DNF for a hot shower, breakie at the hotel and then came back to watch the BF come in on the bike / suffer the run.
Race organization is top notch. better than IMNA / WTC in terms of schwag (included killer race bag, bike jersey, water bottle), meals, awards, etc.
the course, well, it does not get much nicer than swimming in the Med. crystal clear, nice sandy beach, wetsuit friendly. in a word, outstanding. the bike? well, the bike is for a lack of a better word… monstrous. i’ve done IMC, IMLP, IMCDA, and Wildflower like 7 times, and I can say without a doubt in my mind, the bike course makes any of the others like a Saturday stroll on the beach. i live in Boise, with a 16 mile climb up 4000 ft in my backyard and I can say that even riding that, would not prepare me for the ugliness of Monaco. it’s not only the ups, the downhills, are technical, and on very rough, NARROW roads (although I heard they removed one of these sections from the course recently), and nothing like we have here in the US. i would go road bike with clip ons with the lightest set up possible. the run was a loop de loop affair, right in downtown Monaco and goes by the famous Casino 4x, and finishes there. one nasty hill per loop, but generally flat along the water and through the harbor. scenic and the mega-yachts in the harbor only reinforce that you are a broke-ass loser 
if you are going to do this, i’d suggest you make several appointments with the Berkshires and climb Mr. Greylock or other such nasties to get yourself acclimated to some real climbing on the bike. also, rent a scooter one day and check out the course beforehand for mental notes on the hills and road conditions.
the town is cool with the event, and the Prince himself hands out the finishers medals.
we flew into Nice (Delta), and used a hotel / transport package that the race offered. we looked on our own for a better deal and after searching for a month, realized the race tour packages were quite reasonable. for instance, the package offered free breakfast at the hotel (Marriott in Cap d’Ail - very nice) which normally runs 25 Euro a person, and it was included in our room rate (about $250 / night? and unlimited bacon — yummmmmm), airport transfers (by far the biggest pain in the ass and quite expensive).
Monaco is NOT cheap. Be prepared to spend big money for food at restaurants. You do not need a car and can walk or take the very easy to find, local, cheap, buses everywhere. Parking looked like a very expensive proposition and extreme hassle. Rent a scooter for a day or two, definitely the way to go.
After the race, we took the race / hotel transport bus back to the airport, picked up a car, and drove up to Provence for 4 days of chillaxing (maybe 2-3 hour drive from Nice airport). BF got to climb Ventoux while I worked on expanding my ass on fine wines and excellent French food.
If you decide to pull the trigger, PM me and I can tell you all I can on the cheap and easy stuff I remember. Overall, despite the fact that I was crippled, could barely walk, much less ride or run, from my injury, the whole deal was pretty outstanding.
Good luck, Sue