I tried a 2 x 2.5 mile tempo intervals yesterday and it went fine until the last 0.5 mile. It was slightly uphill and I just died on it. So I have plenty of place for improvement... My pace was also quite inconsistent - I ran some 6:36 miles and some close to 7 min. The first interval averaged at 6:41/mile, the second one was 6:40 for the first two miles, but the last 0.5 mile brought it down to 6:46/mile.

I also ran most of my HM race route on Monday (almost 10 miles of it). It is very flat, wide streets, long straights, so it is a perfect course for great time.