I'm on the same page as Bob I think, but I will go a step further and say buy blue in your case. I am assuming the TZ24 is a little bigger than the BX (I don't know the specs on it though).
After typing the following I realized since I don't know the specs on the TZ24 I probably should have kept my mouth shut /forums/images/graemlins/blush.gif But since I didn't, well just take what I say as a recommendation to consider something larger than a "bx size tractor, whatever the color... /forums/images/graemlins/smile.gif
Why? Simply because I doubt that I would be happy with my
BX2200 on 5 to 7 acres, if the land was other than real smooth.
The BX is pretty low, and has things like a plastic cooling fan and filters under there just waiting debris to damage them. This is the case to some degree in tractors that have more ground clearance...to me ground clearance IS an issue with my BX. For others it may not be.
More importantly, the BX 3PH is a major shortcoming in my view. While you can make a simple modification to help correct it, it still is limited even if you do something to make it better.
If you are going to have one tractor, and if that tractor is going to be expected to do a lot of things in addition to mowing grass, I would myself buy something a little larger than the bx. Color is secondary to functionality in my opinion.
It would be helpful if you would tell us what you expect the tractor you buy to do for you. If you got 7 acres of grass to cut and just want a reliable tractor for the long term to do it with, well the BX might be perfect for you.
Then again, if that were the case, we just might recommend a zero turn mower... /forums/images/graemlins/grin.gif
Seriously, the 3PH on the BX is a thorn in my side, but only because I have another larger Kubota that I would like to share implements with. Mini implements are available for the BX, and I am sure if one had them and a bx, and knew no differently, that he would be pretty happy having such a set up, expecially if moving up to it from a lawn/garden tractor.
Still...for 5~7 acres I would go a little bigger than the BX...especially if the price were about the same...or if I could afford a bit more...