What IC do you have currently? S3? 50º on a 25º day isn't that bad, to be honest. I remember IATs hitting 70º in my MK4 days with the side mount coolers I think the ECU starts pulling timing at 45º from memory, so keeping it lower than that is a good move
Interested how you find the DO88!
I was running a THS replica sold by Darkside Developments as an S3 IC upgrade.
This last Monday I had time to take my car to the workshop to have the new IC fitted. It was ordered directly by the workshop so I didn't have to pay any delivery costs, fortunately.
It came well packed. To my surprise, it's painted grey.
I thought it was bare aluminium. It has a great build quality and I liked the fins' design.
Fitted in its place.
When we took the front off we noticed a small gas leak on the front of the AC condenser. A quick call to the supplier and it was possible to source a new one in a short time. Not sure if you know but all new OEM AC condensers are bare aluminium, so the OEM supplier only had those available. Nothing that a bit of high-temperature spray paint can't solve.
I also had the VWR intake cone filter cleaned while waiting for the AC condenser.
When I test drove the car for the first time I immediately noticed an easier spool from lower revs, so the core design really makes a difference in daily driving.
I can't speak yet about the do88 IC's performance at continuous WOT driving, because of lack of opportunity and it has been raining lately (it's also much colder now, 11-12ºC).
I only had time to recharge the AC yesterday.