The spring systems have not changed allot over the last twenty five years. Torsion springs are the most common spring system then extension springs come in second and rear mount torsion comes in third. The torsion spring system is the best spring system when it comes to counter balancing the garage door. Torsion springs have the same amount of tension on both cables allowing your garage door to go up evenly. Extension springs have an individual spring for each cable which causes the garage door to sometimes pull up harder on one side. This causes the door to sometimes shimmy it’s way up but you can adjust the cables and extension springs. Rear mount torsion springs can be adjusted so the garage door works well but it normally means you have a very low ceiling. When you have a low ceiling you may need low headroom double radius track with the rear mount torsion springs.