I helped spec out a CL300 at my previous Company, although I left before going to training. Hopefully someone has better info than me, as I'm very curious too.
This is what we liked CL300 over the G200:
Flat Floor throughout cabin
IMO, the G200 is better in these areas:
It has IRU's as an option, something to consider if doing extensive International
Range is greater, TEB-EGGW. I'm not sure about the return
Gulfstream Support Worldwide
Our owner looked at both the CL-30 and G-200 when he was shopping a few years back. One thing that came up was the range with seats full...the G-200's range was limited with seats full, combined with the hot and high performance, as well as the out dated cockpit compared to the CL-30, the CL-30 was the choice for us. The CL-30 might have a smaller baggage door compared to the G-200...but Also consider the pass through baggage compartment in the 300, not in the G-200...I wouldn't say the cabin is bigger...maybe wider, but not nearly as comfortable as the CL-30.
It's clear that the CL-30 cut into the G-200's sales. The G-250 will be everything the 200 isn't and a bit better than the CL-30 in every catagory...same motors as the 300 but a bit more thrust, IRU's, a bit more range, new wing (no boots) ...the list goes on...it will be the plane to have if you look at the numbers.
It's true that the CL-30 is lacking for serious overseas operations...a lot of guys don't like the lack of IRU's, and such...but I can say that it does everything as advertised and does it well. Bombardier support is and always has been a problem. Mechanics like working on it (atleast ours does.) Passengers like it, the operating costs are great and the list of negatives are few. Biggest problem is getting one, although I have seen a few listed for sale since the down turn in the economy.
That's a question that has come up several times since the start of the program. Bombardier's answer is that it was never intended to be an international airplane...remember it was originally the "Continental" intended for East Coast to West Coast operations...it wasn't until operators started taking the aircraft overseas that the IRU issue and lack of some redundancies came up...there has been some testing of IRU's in various installations...Bombardier hasn't said if they have any immediate intention of finding a solution...but I would guess that when the G-250 hits the market it won't be long before you see it as an option at the very least.
If you're primary operating area is North America, I'd go with the CL300. However if you're planning on International operations, Look at the G250 and have Gulfstream put you in a G200 while you're waiting for delivery. I believe they will buy it back from you if put in the contract/
And plenty of furloughed Flexjet pilots willing to fly it. Cheap!
Baggage isn't an issue. I've had 8 sets of golf clubs and overnight bags in there, with crew bags and international kit. Bring big things in through the cabin. Passengers do love it; only issue I ever had was small trash can and not enough storage for catering when you have 8 folks on a cross country.
I fly the CL30 so I am a bit partial. The G200 has a nice cabin and the owner will like that. From a pilot standpoint the CL30 is better, and a better performer. The new G250 will be awesome and I suggest if you are waiting a bit to look hard at that. I've been on board a Hawker 4000 and the cabin just feels small. The whole plane looks smaller, but that is nominal. Right now IS the time to buy a used 300. I know you will not be upset. Anything bigger than the Lear 55 will give the passengers more comfort, and you will enjoy flying any of them.
If you are not looking only at new, a company on our airport did his same drill and ended up buying a used 604. There have been several 604's sell in the 10-12 mil class. Fuel burn is more, but far less dollars. They also compared Falcon 2000 / 50EX / 900. There is a good market on the 50EX right now in my opinion. Cessna and Hawker are getting pretty aggressive right now on new as well. Our New Hawker has been a dream. We do not stretch the aircraft however. 900XP is pretty impressive.
I fly a G-200 in a dept that has a CL30. I've not flown the Challenger but I can make things pretty simple.
From the back of the cockpit seats forward the CL is superior. From the same point all the way to the APU exhaust the Galaxy is superior. The cabin in the GALX is far and away the better of the two in terms of amenities, finish, galley, everything but the pass-through baggage. And the flat floor that the challenger guys rave about to me makes the interior look even more like a trailer. It even has a bizarre smell (ours do, at least).
All that having been said there is no mistaking that in terms of runway performance the CL is again superior. The GALX does okay until you thrown in runway contamination, then you're just about d*uched.
The GALX is a little faster, burns a little more fuel and won't shoot straight up to the 40's the way that the CL will. Gulfstream support is vastly superior to the Bombardier support as has been said.
At the end of the day, the G250 will be the best of all three if you can wait. If not, there are A LOT of G-200s on the market right now. CL30s, too, I think.