FWIW and i couldn't give a rats if you take heed or not, rather than thinking about "linear or roller" think about the bio-mechanics of the equipment you're looking at.
the difference between linear versus roller comes down to friction, some value minimal friction in exercise, especially the "super slow" peolpe.
The path and range of movement of a properly designed machine is based on muscle and joint function, a well designed machine can be adjusted to allow for correct positioning and alignment providing a safe path and range of motion for most body types.
A machine that is properly designed, and if you are correctly positioned and/or aligned and performing the exercise correctly you aren’t going to be injured by it.
if not, you don't use it.
There are heaps of machines with axes of rotation in positions making proper alignment difficult or impossible for some
Use a machine that is properly designed and used correctly it will not cause a repetitive motion injury either as long as you are performing a reasonable volume and frequency of exercise.
In the last 30 years there has been a flood of equipment on the market, prior to that there was only "universal" nek minut Nautlius.
Nautilus spent 10 years of development and millions of dollars research before they released their line, all the rest are copied their designs one way or another.
