Springs will compress as they age and need to be replaced regardless of the brand of springs you run. Most brands are compatible with each other and TEKNO springs tend to last longer than most other brands before they compress and lose their ride height capability.
Once my springs compress to where the shock collars can no longer maintain my desired ride height, I replace them... I run HB springs on my HB buggy and they tend to last around 4-6 months of racing before they need to be replaced. I run TEKNO springs on my HB truggy and they have been going for over a year on the first set of TEKNO springs.