I have been working with tractors with rear chains for 30 years. I recently put the v-bar chains on the front of my CK20. I could not use rear chains without removing the 4 pt. backhoe frame made by Woods.
I really like the front chains.
My first choice would be front and back but in an either or, both have advantages but I have to say that having tried both--front is my preference.
Using the HST, chains on the front, blade and FEL--I have cleared some major snow and enjoyed doing it this winter. The only time snow removal got tedius is when the CK20 was down for a week and I had to go back to a gear, rear chains, blade and FEL. I missed that grab of the front chains, gear took so long for the front back front work.
The Rockwell scale on those chains from TireChains is 360, which is good hardened steel at a good price. I bought the spring tensioners and am pleased with them and would recommend the tensioners.
Good luck with your decisions.
CBB