How bad is the performance seat compared to standard seats for comfort?
Is it a marginal different or a substantial difference? What about for long drives
Would love real world experiences!

Thanks!!!

There are many threads on this topic and unfortunately nobody can really answer that question for you. Comfort is subjective to a large degree. We humans come in many sizes and shapes. The standard seats use a somewhat softer cushion material, but the main difference is really that the performance seats are much more snug with the aggressive side bolsters, although the side bolster are adjustable so for a more comfort fit you can fully deflate them and for more lateral support you can inflate them. Now again, the comfort comes down to how many extra pounds you are carrying around and how well you fit in them. German cars are designed and built around the average German male who is 5'9" and about 170lbs. So the farther off you are from that the likelier it is that you'll feel discomfort. BTW, because of that women are more likely to die in a car accident than male and more likely to get insured or experience discomfort.

Now I can tell you from my perspective. I have them in my C63S coupe and I absolutely love them. They are one of the best seats I've ever had. In the C they can be had heated & ventilated as of 2019. I believe in the GLC the ventilation isn't an option, so that can be a significant factor between the standard seats and the performance seats. The ventilation definitely makes a big difference. But as far as seating comfort goes in general, I have absolutely no comfort issues even on longer drives. My longest drive so far was about 12 hours in a single day. I did European Delivery and drove from Switzerland all the way to Copenhagen, Denmark in a single day. No issues whatsoever and that was not the only long drive like that. I do a lot of grand touring easily driving 6+ hours in a day. I much prefer seats with a lot of lateral support, because believe it or not, but they reduce back fatigue as they keep my body upright w/o me having to use my back muscles much. Especially the performance seats since I can tighten the side bolster when I hit up some fun twisty road and they keep me in place w/o sliding around. They do make it more difficult to get in and out of the car as you have to get over the side bolsters, but that's not really an issue for me. Good core strength solves most of these issues.

Ultimately as I said, your fitness level and body shape will have a lot to do with how comfortable you'll find them.

I have them and love them. comfortable on all of the road trips i've taken in the short time i had the car, including the 10 hour drive home from the dealer.

I only worry about wearing the side bolster getting in and out of it. So far, looks like new

Wow, thanks for your detailed response. I have to say what you mention rings true.

Ive had mostly sports cars my whole life and never had problems with seats but recently I find I get back or neck pains when I drive most luxury cars, I think it's the combination of leather which lets your body slide and the lack of bolstering, forcing you to constantly adjust like you mention.

The best seats I've had in any car so far have been in my w204 c63. They seem to have good padding, good bolstering and use dinamica which is adds that extra layer of padding and grip.

From pictures it seems like the stock glc63 uses similar seats but I can't find any in dealer stock to sit in. They all seem to order cars with leather seats.

i did find one with performance seats and the extra lateral bolstering is a bonus to me like you.

Im mainly worried about how much cushioning will be lost with them and if thy will feel like church pews. In that case maybee I won't get back pains but will get a numb butt after a long drive. Lol

Thabks everyone!

So if you are used to sport seats, then I wouldn't be concerned about the performance seats at all. In terms of cushioning I find them no different than other sport seats. On longer drives I do regularly change my position, but that's just normal. Sitting in the same position for too long naturally causes numb bum regardless of what I sit on, unless it's like a really soft cushion. I had Alcantara (same as Dinamica) seats on my previous car and I liked them. Even with sport seats in the past I was sometimes sliding around on the leather, especially as the seats wore and the leather got more slick over time, so the Alcantara kept me in place. I don't know about the GLC63, but the C63 only comes with leather. I really wanted Dinamica, but it's only an option on the 43. Now that I have ventilation, the sweaty back syndrome is not an issue, which was another reason I went with Alcantara previously, and as I said the adjustable side bolster can be made tight enough so that I don't slide around.