It depends on your land and intended usage. My dad's farm, about 15 miles away from mine, is well drained, and he gets by fine with just 2wd tractors. At my mucky, bottomland place, I got by with 2wd tractors for many years, but I always held my largest one in reserve for the times (usually once or twice a season), when the mud got the best of the second biggest one. I would never again be without a 4wd, since getting one 6 years ago. My spring planting has got finished an average of a month earlier, and I have not been stuck since. You mentioned that the tractors have loaders and that is another big strike against the 2wd. With the 4wd, that weight ahead of the front axle adds to your overall traction force potential, unlike the 2wd where it subtracts from it. I always leave that loader on my 4wd when I am doing risky field work, and there has been several occasions, where I have used it to pull or push myself out when I manged to loose traction on all 4 driven tires. A 2wd tractor cant even get out of its own way in mud with a loader hanging off the front, which forces you to pull it off before trying to do any serious field work. Another thing to consider is fuel usage. I will guess that any job involving loader work, or operation in soft ground (tilled or mud) is going to take around 25% more fuel if using a 2wd tractor compared to 4wd. That there is the main reason we are not likely to see any big 2wd tractors doing serious tillage operations any time soon. There is a steep energy price to pay for pushing a dead axle thru the soft ground. If all you are doing is mowing and/or hay and never have to contend with mud then the larger 2wd may work for you.