I am not sure Larry helped, but here is a shot.
There are two main differences with Transmission: Hydrostatic and Gear. Now gear transmissions have a lot of variations. Syncro is a gear transmission. Now with Gear Transmissions, you need to to clutch to change gears to get a higher Power (gear) or Speed (range). Hydrostatic, instead of gears, the transmission is operated by fluid (the Hydro in Hydrostatic). The flow of the fluid in the transmissoin determines the direction you are going (forward and reverse pedels) and the amount of flow determines the speed and power. You can change speed and direction without stopping the tractor.
With the the Gear transmission, clutching is involved to changing speed and ranges. With some tractos, to change gears, you need to clutch and stop the tractor to move up or down. You may even need to stop the tractor to change direction. Well, If you have to do a lot of loader work, change speeds lots or anything, having to stop the tractor really eats up productivity. Thats where synrco comes in. Syncros, all you have to do is clutch and move the gear lever to what you want to do, this slows the tractor but at least it helps. Also, there are Left Hand Reversal Models. These do not do anything for speed or power, but for direction, to go from forward to reverse, there is a switch (which looks like a signal light switch in a car). This great for loader.
Gears do have more wear points, and will break down (normailly) before a Hydrostatic transmission will. Gears is more cost effective, so less money option.
But Hydraustic is the place to be. Easy, more effecient, and in a lot of cases are only $600 to $1200 more. Peanuts in the grand scheme of things. Go for the Hydrostatic, as the resale value will be enough to convince you.
There are three hydrostatic models (Hydro, ehydro, AutoHydro). I am not going to go through them now (you can reply and I will). The difference in these models is reletively the small. The all operate the tractor the same, difference is more systematic within the machine.
Now as for the 3203 vs BX24. I do have concerns that these tractors are not close to each other to compare practically. 3203 has 32.1 HP where the BX24 has 23 HP, apples to oranges. The John Deere 2305 would be more comparable.
Now as long as you do not plan to move bales, the 3203 is a very economical choice. The 3203 is John Deere answer to all the Kubota's, New Hollands, AGCO, Mahindra, etc, that produce machines based on price. Deere has always had a mentality that their machines need to be user friendly, and full of comforts, as well maintain an impectable part and service reputation. Other brands, go out and sell machines on price. Well, with less price comes less machine, less service, and less part availability. Many manufacturiers have a 5 year limit on parts they sell and stock. If a machine is over 5 years and you need a part, well they will pass you off to a supplier and hopefully it is in stock, if not, they will need to build it for you which cost time and money.
That is why Deere has a hugh resale value, because people repect the quality of the Deere, and will pay more.
Well, despite the quality mindframe, and due to the current US financial state, Deere produced the the 3203. This machine does not have everythine a Deluxe model would have (the 3120 is the "high end" brother of the 3203). It does not have folding roll bar (if you have trees, low garage door, could be a problem) , no dual brakes (used to turn the tractor faster), less seat suspension (sit on both tractors, that will probably sell it for you), no mid pto (so you not be able to put a mid mount mower or a front mount snowblower), less lifting capacity (3203 with a 300 loader will lift 740 lbs vs a 3120 with a 300x loader will lift 1358 lbs), and here is the kicker. The 3203 does not have rear hydraulics. John Deere Backhoes will be out of the question, as thier backhoe plums into the hydraulics of the tractor.
Yes there is other shortline companies that sell Backhoes that run off the PTO (but you need to buy a separate pump). Shortline is a term for fly by night companies that produce a piece of equipment then they drop the product line for future models - sometimes even changing names; MTD is famous for that. What that means, they will be here to sell you the machine, but when you need parts and service, they will be gone, leaving you with a pile ot junk. As well the machines do not have the quality behind them as John Deere has.
The 3203 is still an excellent choice for landscaping and spraying (though the 3120 has a cruise control miles per hour gauge, the 3203 doesn't). It still comes with the parts and service backing that outdoes any manufactural hands down. It has the height advantage and floatation that the BX24 does not, and the traction the BX24. As well, resale value on the John deere machines alone should be enough to convince you. Yes you may pay $3000 more, but you will get that in the end, on a machine that is heavier duty and user friendly!