Skylane-
If memory serves me correctly the 210 began production in late 1960 and was basically an RG 182 with an IO-470 (260hp) and a "chin" on the nose gear doors. In '64 the engine was changed to an IO-520 (285hp) along with the addition of 3rd row folding "kiddie" seats. In '67 the strutted wing was replaced with the cantilever wing, in '68 the hydraulic flaps were replaced with electric, and in '69 the "chin" was removed from the nose gear doors.
1970 showed some of the most notable changes: the gear was changed from spring steel to tubular steel giving the gear a wider stance thus allowing the gear buckets to be further aft which allows for 3rd row "full" seats. The gross weight was increased by 400lbs and the engine was upgraded to the IO-520-L (300hp). I cannot remember for sure when the final wing change was made but I want to say it was in '72 when they took some of the dihedral out of the wing to make it faster, but it sacrificed some of the ground roll. Other changes were made throughout the lifespan of the aircraft, but these are some of the most notable. It is hard to compare apples to apples on different year models of the 210 for this reason.
We had a '69 Cessna 210 and I would not trade it for any other 6 place piston single on the market (except for an newer model or maybe a T-210) when it comes to long cross country or hard IFR. The 210 is rock steady and handles very well even in rough conditions and you will be hard pressed to load any others the same way and get it off the ground without the controls feeling a little mushy. I have a few hundred hours in the 210 including a '62, '64, '69, and '72 model. I only about 10 or so in an A-36 but that was all I needed to know. Apples to apples a 210 will out run, out haul, and out range a Bonanza on any given day. They are cheaper to maintain, easier to fly, and they don't wag their tail all over the sky like the Bonanza.
The Bonanza does have it's place in aviation, they are the stereotypical status symbol for the more "well to do" and Beech continues to market it's aircraft in that way. It has 6 seats in a club seating arrangement as well as a "business desk" for those who actually work in the back while flying and it always has the highest quality interior that can be installed in an aircraft. You must be careful in the Beech products as it is very easy to get AFT of CC long before you reach MGTOW
If you are looking for an airplane that is ready to work hard and go fast then you are looking for the 210, but if you want luxury and status then you are looking for the Bonanza.
Just my .02 worth.
