
This is from my riding buddy Dean who got a new set of these wheels last week:
Really enjoyed the ride on these. Fairly basic 70mile ride on the flats with some hills but nothing more than 3 to 4%.
Little in the way of cross winds so couldn't test how stable they were in winds. Had a hard ride for the previous day so prob a little tired but didn't really feel it so gave the 303s a good workout for 3.5 hours.
My only comparison are the Edges (which sucked in cross winds but were awesome in a stright line - you know I have always been a huge fan). These felt similar in speed once up and running and as the bearings wear in (the G3c feels like it will take a few longer rides to get bedded in) the 303s should get smoother and feel faster. Must say though that the Edges were probably a little easier to spin up and felt marginally easier to climb with from memory. Difference is really marginal and may be I have rose tinted specs for the Edges but the 303s show that the Edges were also great wheels.
I was also probably fitter when I rode the Edges and I think that makes a difference right now in getting them going properly.

Having said all of that I thoroughly recommend the 303s. The ride with them is really comfortable and I was really impressed by this - no banging the undercarriage and took rough roads really well - and they feel solid and I love the sound of them rolling along. The av speed from yesterday just shows how they can cruise and I could climb at least a gear up on normal wheels and once I get another 30w I can feel they will really roll on the flats in a bigger gear.
These are a fast man's wheels to get the best out of them and I am not quite there yet but when you want to go hard they go fast and they climb well on a steady wattage. I need slightly more power to test how they spin up as I am a bit sluggish still on stepping on the peddles hard.
Do not get the corks pads - they squeal and did not brake as well as the Swiss stop Grey - I will give them another couple of rides to see if they bed in but Swiss have good stopping power, don't grab at all (but I did not get them anything like hot) and feel easy to read on how they will decelerate you.
[Barry's note - I gave Dean both the Zipp cork pads and the new Zipp grey pads to see which ones he preferred]
I will give you another update when I next get out but thought I would share and I will prepare something more thorough for the blog next weekend.
Definitely worth getting a pair - I will take stability over a fraction more speed given the riding we do. They are still fast enough.
Warm down was really smooth and really noticed how well the wheels ride at lower speeds.