Ruth, I've used Smart Coach to train for a 10k, having completed a 5k on a different programme. I had a few hiccups in my training by getting ill etc. but stuck with it, I was 1 week off completing the schedule because of being ill, but ran the race anyway. I'd never done more than 5miles and usually around 10.40 pace. I started out with a goal of completing in less than 60 mins, but accepted towards the end that if I could do it in 1hr 10 mins or less I'd be happy just to have done reasonably well. As it was, the adrenaline kicked in & I ran it in 58.24 with only 1 mile of the 6 under 10 mins - not something I'd have believed possible and something I have deliberately avoided doing in training - I knew I was capable of running faster, but not for very long stretches.
Reading through this thread there's been a lot of critcism of smartcoach, and I kind of understand. When I started using it, I compared it's 5k plan to the one I was using & was baffled by it. Then I started messing about entering times I thought were better to see what changes it made. After getting the hang of what it was doing - starting you slower than you usually go, to work on endurance, and building up speed - I began to understand it. I tried different times/speeds/ easy/hard etc. and thought them all through. My main complaint would be that I can't see a way to change from 3 days training to 4 and I'd prefer to do 4 and spread my mileage over that (no real reason except I try to run at lunch time and so short of time mid-week), however, by using the easy or moderate settings I decided that I could shift up to 4 days a week shortening the timetable by a week or so IYSWIM.
I've now asked it for a half marathon plan based on my 10k time (not that I have a HM to run until next year), but wanted to see what it would do. The average pacing is good and manageable, and the speedwork is challenging - a tad faster than I ran today, but I know I can do it 'cos I was checking my pace regulary and know there were times I was hitting these paces and could have sustained them for longer if I'd had to.
So all in all, I don't think Smartcoach is as good as a real person, but if you're alone & needing goals - it works on getting you going further and my experience today makes me feel that's the best way to achieve. Timing can come after you know you can handle the distance easily.
Roslyn