My running partner is gearing up for a half-marathon this winter in San Fransisco and she is following this plan. I have been joining her on several of her shorter runs as well as her longer weekend runs. One of the deficiencies in my running is I often run just for miles. Joining her on her runs gives me a lot of needed variation at shorter distances. I have been able to fit more runs in per week than I normally do and now can comfortably run five days a week (in fact last week I almost found myself running six, but took Sunday off as a rest day.) The only draw back is having to deal with running extras (prep, cool down, shower and cleaning my gear), not to mention getting up earlier to do it. But the early rise is not a huge deal, I like getting up early anyway.
She just ran a 10K this weekend and did pretty well, so I felt like I had to push the pace. Overall we ran faster than 9 minute miles on our 4.25 mile run. To start I think we were probably running 8.5 and then faded to 9.5/10 towards the end (especially on that darn hill coming out of Reed. I think adding the chit-chat on ourr runs gives us an extra physical push as well, certainly pushes the breathing.