John,
I have owned swingers, CaseDavis, Gehl Advantage, over the years in my tree biz. I am a boxer dealer I have ran the boxer Articulaters on some demo and till lately I highly recommended them but I have to tell you support and parts have been miserable.
I am also a Gehl articulating dealer and have been waiting for these machines to get released in America. They have been making them for Europe for the last 3 years. I got a chance to operate a Euro 140 at my shop last summer and checked out all 3 models at the factory in West Bend. I am supposed to take delivery on 3 of the 1st ones made for N America in a week or so.
The Gehl is twice to 3 times the machine boxer/multitrak/multione is, plus the cost is less than the Boxers. Also they are American made backed by a 150 year old company with excellent support. the only other American made Artic available is, I believe the swinger, the Wacker is German, another nice machine but spendy.
The Italian machines are pretty sweet but maybe a little under engineered for the Power they have. Even worse news is CPI just dropped the line so there are no more distributors for that machine in America. Parts are going to be a son of a B in the future, and already are in some instances. I would recommend staying away from the Multis for that reason and a number of stories I have.
The side by side is a Gehl 140 and Boxer 726, It looks a lot larger but the footprint is not that much bigger. I like the fact that they are using tried and true Skid steer components, and the chair does not swing outside of the wheel tracks. The only thing the boxer has over the Gehl is its super light weight ~2200 #s and the 140 is 3500#s. Otherwise there is no comparison the Gehl is ALOT more bang for your Buck.
I will be bringing one down to ISA in Chicago, I can get you a good quote on one.
http://www.gehl.com/const/prod_al.html