Expensive but worth it.
On the positive side, telescopic runners are a fantastic improvement over pulling out a shelf the old fashioned way: jerky and screechy. I have 2 sets of runners and I feel much more in control when adding, checking and moving dishes around - I imagine the next time I have something delicate to check on (like crème brûlées in a Bain Marie or a cake) or something heavy like a turkey, I will appreciate how smoothly they glide out even more. On the negative side, although you can keep the pyrofit runners in during high temperature cleaning process, the little ball bearings need to be oiled (with your cooking oil of choice) afterwards, so that doesn’t seem much of an advantage since presumably you need to remove the runners to oil them or risk getting oil on your newly clean oven. Miele do 2 sorts of telescopic runners: these and some that have to be removed during cleaning. My oven was supposed to come with one set of each as standard but the non-pyrofit set was missing so Miele kindly couriered me a second pyrofit pair - if there is a price difference, perhaps the non-pyrofit ones are worth considering for the joy of telescopic runners if you are already at the top end of what you want to spend. I should have asked more questions about the differences between them … but something, something about gift horses and looking in their mouths…. The second negative I discovered is that the runners wouldn’t fit in the top two positions in my oven: you are told in the manual that you can’t use the temperature probe if you fit them in position 4 (second from top) but I couldn’t fit them in position 5 either. They appeared to be a bit too wide/tall for the side rails. If it is important to you to have runners on your top shelves, I’d recommend a trip to a Miele showroom and asking the staff to demonstrate fitting them in all the different positions. In the end, I fitted them in positions 1 & 2 which allows me to roast a chicken on shelf 2 with potatoes and veg in dishes on shelf 1 below the bird. In any case I only need to use the top shelves when I’m doing a lot of baking (rare) so it’s not a big deal for me, although I originally had visions of fitting runners on all the shelves. Bottom line, if you are going for an entry level oven where a set of runners isn’t standard, it’s one of the best things you can add. If I had to sacrifice, I’d rather have runners over a built in temperature probe or steam function.