I'll let folks know how they work I ordered a kit for my 550. Thomas Duncan of Vintagecarled's sent me a free upgrade to my out of stock order.
Here's what he wrote me:
Pete, these would fit just fine if not better in your 550
The heat sink and fan has been moved inside the lens, which warms the air thus warming the glass lens (to melt snow and ice etc)
We found the high/low beam is much more improved too.
Let me know what you think.
I'd strongly recommend them over our 2500 model (the one with the external heat sink)