I'm breaking my rule and doing a gear review!
A multi-sport kid carrier is the quintessential must-have for active young families. Julie and I got one before Finn was born as a joint baby shower gift. They are expensive with all the add-ons but they become a way of life and open up a multitude of early life adventures that would be difficult otherwise. I use this thing almost everyday of the year, it's been through the wringer.
The one we have is the Cougar 1, it's the 2010 model, some of the things I'm critical about might have changed with the current version. It's worth having a look if there have been improvements before judgements are passed on the new ones. We use ours in Bike / ski / run configurations (in order of use as well) I'll go through each one.
This is where the Chariot shines. The suspension works and your kid is well protected, the bike attachment is solid. Try as I might I have not been able to break the rubber ball joint that attaches to the bike hitch, it's an amazing piece of simple engineering and material selection. The safety backups need serious re-thinking however as the clips and webbing run dangerously close to disk brake rotors. I skip using the backup all together due to the poor design and high frequency at which I attach and detach the hitch. The bike mounted socket works best with flat drop outs on steel frames. You'll have issues with "inset" dropouts and have to run the wheel slightly to the back with Surly horizontal dropouts. If you have an alloy frame you need to make sure the QR is very tight to prevent motion of the socket piece and eventual grinding of your (softer) aluminum frame.
The cover does a decent job, but could be improved upon for use in heavy rain. The clear window material starts to yellow after about a year due to UV. At 2 years (stored 50% of the time outside) it's pretty yellow and could use replacement.
Bike use with an infant - I got my hands on a used "infant sling" that basically clips to interior D rings and cradles the little people above the main seat. Its seriously overpriced if you need to buy it new. It works well, but it raises the center of gravity of the load making the trailer more tipsy. I flipped the trailer once while biking with Finn in the sling and it's a show stopper. After that I had a full dromedary bag as ballast in the bottom of the carrier. Makes things heavier but its more stable when dealing with curb ramps and tight turns.
Another great aspect of the bike mode is that the skis for ski mode can be used with snow bikes for a smooth sailing winter bike trailer.
My only other comment is that the plastic hub covers fell off within a few weeks of use never to be seen again...
The ski mode is awesome, however prime use of it is fairly short lived. It's best use is with infants to 18mo olds, and skate skiing. It's a sleep machine, so is a good way to get exercise during nap time. If you are strong you will be able to skate ski anything you normally could pulling around your infant. I got 6 pack abs and gigantic shoulders after skiing with Finn his first winter. Classic skiing is not good, slow and not my idea of fun. I'd rather bike with the ski's mounted instead. If you just want to cruise around on classic waxless scaled skis then it does the job just fine however. So the first winter when your kid is little is awesome, it gets quite a bit harder on the climbs the second season. This is Finn's third winter and I have not even tried it. Skate skiing is all about technique and towing 50 lbs just does not sound like fun.
The ski package has a few minor issues. The stock hip belt needed a different combo of webbing and buckle to stay tight. I had to cut out the webbing and sew on regular backpack web that would not slip. Major overlook on their part.
Secondly - the poles, they work, but the plastic inserts get loose and slip out, this leaves a lot of slop in the system and I've had to stop countless times to shove them back in. Super glue or epoxy them in place from the get go! Also, pad the chariot poles with pluming insulation or some other foam, your $150 carbon skate poles will thank you...
The waxless skis work as expected, ours need a major stone grind / belt sand at this point but are still fine for pulling with the bike.
Lastly, some better quick release for the poles to the Chariot would be nice. it can be a pain fumbling with pins in tight places in the cold. But they are simple so that's not a bad thing.
The Cougar Chariot in run mode is really a "walker", and works fantastic walking on dirt paths and wide trails. True running strollers are much lighter, have front wheel tracking adjustments (and larger wheels) and handle with minimal input from your hand. The Chariot's suspension makes it handle like a tank if you're trying to run with it. It also lacks a height adjustable push bar but they are available as expensive aftermarket items. It get's the job done, but is kinda a last resort
A few more detractors... the parking brake is awkwardly located under the flip up pocket. Julie did not even know it had a brake for 2 years since it's so well hidden. The parking brake foot actuator also tears through the pocket fabric exposing the inner plastic sheet in time. To avoid hitting your feet on the pocket when running it needs to be locked in the up position, unfortunately the quick releases don't lock well at all and it slips down easily.
Bottom line - the run mode is really makes it an all terrain stroller, if you plan on running more than biking or skiing with it then get something else, or look at the higher end CX models.
Sum it up - If you are expecting a kid and lead an adventurous life, you can't go wrong getting one. They become intertwined with your lifestyle and I cant imagine the last 2+ years without one.