Yeah I've done Arrow Valley.  Really good, very friendly - I'll be going back in a few weeks but I would strongly disagree about it being as quick as Pitchcroft.  Definitely not as flat as there are a few peaks and troughs along the way.
The only Parkruns I've done that can rival Pitchcroft for speed are Hastings (simple out and back on a promenade) and Isabel Trail (out and back on what I think is an old railway line).
What colour have you gone for with the Pro 4s?  Very exciting!
		
		
	 
There are 3 problems with Pitchcroft, it's like a tundra, the wind at the bottom end can be awful, the 20 metres of bark for the horses that you run through twice is horrible, and finally the sprint finish is on grass, which can be boggy.
AV does have a couple of ups and downs, but obviously you can earn that time back on the downs, i like that the second lap is different so it avoids the traffic of the slower runners, the wind doesn't seem to be too bad, and it's paved all the way around.
However, i have only done it 3 times i think, and in each instance i was in really good shape, so i probably think better of it as a result, where as i've done Pitchcroft so often i've experienced it at its best and worst.
All that said about Pitchcroft, the Horseshoe course is definitely faster, i think that the normal course is either measured long, or the Horseshoe course is measured short (or both!), because I always seem about 20 seconds faster on that alternative course.
As for the Pro 4s i went for these, £152 from Sportshoes seemed pretty good. They look beautiful now, but a couple of damp runs and they will look dreadful...still.
