Matt,
All are good points.
1) I understand that you expect to pay 50,000$ Can (37,000$ US) for a 100+ hp tractor with loader. I have no idea how it works in Europe, in Canada it's simply impossible.
2) Comparison with MF5612 is apples to oranges. Belarus/ MTZ 952 list is 46,200 $US. MF5612 list is about 95,000 $US. You can essentially buy 2 of the Belarus tractors for one MF5612.
3) Over 70% of service calls on modern tractors are related to electronics, computers, sensors etc. Therefore, it makes sense that you need a dealer 45 minutes away for 24/7 emergency service. So it was the right choice for your circumstances.
Belarus tractors are purely mechanical, no computers, no complicated electronics. Factory designed them this way on purpose, because there is no 24/7 dealer support in many of the areas where Belarus tractors are sold.
Farmers buying Belarus tractors are less concerned about having 24/7 support, since it simply has 70% less service issues than most of the complicated competing brands. And when it happens, most things can be addressed on the farm with basic tools and no specialized knowledge.
4) Demo on the farm - talk to the dealer. If you'll share some transportation cost, you may reach an agreement with him.
I do not think that there is a universal answer what's best tractor. Each circumstances require different solution, and hopefully you chose what was right for you.
Happy New Year.