I'm not familiar with the SmartCoach but I have also found easy runs too slow on other plans generated from a previous race time. I think the slower you are the less realistic these easy paces can become.
To quote the SmartCoach blurb:
"Slow runs are slow because that's the best pace for you to follow to build endurance without overtaxing your body."
You can use a heart rate monitor instead of pace as a way to ensure you are running sufficiently easy. If you run below 70% of your WHR that's easy. I found it to be faster than the 'easy' paces in my recent plan but did have to walk up some of the hills in the beginning to keep the heart rate down. I found that over a 12 week program, my pace became significantly faster as I got fitter and I was able to go up many of the hills whilst keeping below the 70% ceiling.
So deep into your current plan, this suggestion might not be of any use but maybe worth considering in the future.
Incidentally you can also use the HRM to make sure you are working hard enough in the hard sessions too. As you get fitter you find you have to work much harder (run faster) to get your heart rate up to the hard level.
Proponents of pace based training are right in saying that pace is really the only reliable indicator of race performance so that is what your training should be based on.
Proponents of HRM based training say that slavishly adhering to pace can mean that you can over train running too fast when your body needs more recovery on some days. Similarly you can miss the opportunity to run faster when your body can work much harder in a particular session.
I blend the two. I get a plan based on pace to get the distances and mix of workouts but I use the HRM to ensure I'm working easy or hard enough. This mostly means I ran faster than the paces in the plan but there are days when I go slower because my body hadn't recovered enough from previous sessions.
But hey, what do I know. I'm just an old plodder that has only ever run two races. Thought it might contribute to the discussion though.
in depth reviews here: http://www.dcrainmaker.com/ might help you decide.
If this is your first sports watch, I recommend buying the cheapest to learn what you really need and then upgrade later.
I found the choices bewildering so I bought the non-GPS FR60 first and used a smartphone GPS app with it. I then quickly learned what features I really wanted as well as finding out that a purpose built watch is better than the smartphone apps. The FR60 chest strap and footpod can be used with the higher end Garmin models afterwards.
Don't know about VO2 Max but heart rate is obviously related and easier to measure. Heart Monitor Training for the Compleat Idiot counsels <= 75% of WHR (or HRR depending on your favourite nomenclature) for the Marathon (<= 70% for first 20 miles if you are a novice).