I believe you should factor in how long you plan to keep the mower as part of your purchase decision. I own a Gravely Compact Pro 34 and a Toro Z500 -52 for my two homes. Considering the size of your property you will never be sorry for purchasing a 52" deck versus a 48" deck. Larger tires will definitely do less damage, especially on wet, soft ground.
You did not take about the spindles on both mowers. Typically, pro models have better spindles.
Good luck on your decision.