A 3 hour tour, a 3 hour tour

Just got cleaned up after a 3 hour run. It's a beautiful Sunday here in the Twin Cities, about 55 degrees and sunny with a wind out of the north of about 10 mph.
I slept in a bit and had a good breakfast of oatmeal, a banana, and a bagel with peanut butter. I guess due to the timing (10:30am), it was more of a brunch. But I knew I needed the calories for the run I was about to start.
I drove down to the Deephaven paddleball court again since it worked well in my two hour run last weekend. I planed to do 30 minute out-and-backs where I run/walk in one direction for 30 minutes and turn around and go back the same way. This gets me to my car for water and gels every hour.
Per Coach Bill, the goal today was 3 hours, 5 minute run/5 minute walk, running at a pace of 7:10-7:15/mile. This was a big challenge since last week was "only" two hours and the runs were at a ~7:35 pace.
Here are my splits/pace for today's run:
1 - 7:05/mile
2 - 7:12
3 - 7:12
4 - 6:55 (whoops!)
5 - 7:03
6 - 7:03
7 - 7:09
8 - 7:07
9- 7:08
10 - 7:10
11 - 7:26
12 - 7:08
13 - 7:10
14 - 7:22
15 - 7:12
16 - 7:30
17 - 7:26
The most challenging were splits 13-17 above. My legs felt a little heavier, and it took a huge effort to keep up the speed. It really took a lot of focus. The last two were especially tough. I truly gave 100% on these, but just didn't have much gas left. In the last 3-4 run sets today, I was breathing very hard, and noticed my breathing became audible for a few seconds after I started walking. Kind of a pant or grunt :)
Overall, I am very happy with how today went. Looking at the numbers, my confidence is boosted. I was a little worried about the length and speed of today's workout, but I did it!
To catch up on the last few days:
Life got in the way a bit on Thursday. I hosted a small dinner and got behind schedule. I was supposed to do some straightaways but didn't make it to the gym. Friday, the scheduled day off, was also very busy and there was no running.
Yesterday (Saturday) I went on a very relaxed three mile run in my neighborhood. I knew I had a tough one today, so I didn't care about pace and just enjoyed the run. Barely broke a sweat.