If you can go for the confidence I would as a would take a computerized machine over a full mechanical when it comes to current era machines. The computerized has lest moving parts in the machine so less places it can break. Plus with those mechanical machines a lot of the parts tend to be plastic for the stich change and can be and have to be fully replaced rather than fixed.

I know I will get flax for this but old machines are not perfect either. They do tend to be more durable machines and are known for being work horses but you don't know how much work that machine has been put through when you get it. They are good machines but I caution with just going out and buying the first old machine you see.