Why not try a 10,000m on the track? It'll be something different, its flat, accurate, you can closesly monitor pace and it guarantees you a decent ranking on po10!! (as long as you do get under 36) the county Champs events are usually end of August, Gloucestershires is always around the last weekend in August. Worth considering i'd say.
I bought them once and really liked them but couldn't really justify spending another £120 when they wore out.
The only slight problem with them is in the first few weeks of using them my calves felt a little sore, however, once i'd worn them in this was no longer a problem and I used them for all speedwork and also on longer tempo efforts of 8-10 miles and had no problems.
Im 28 and been running 2 years, I'm a low 34 min 10k at the moment, I've averaged 35-40 miles a week since January and tend to do 2 quality sessions per week throughout the year (one interval session and a tempo effort) but will include hill efforts, progressive runs and strides when feeling good on steady runs.
Mon: Steady 6-7 miles at 6.35-6.50 pace
Tues easy 6 miles at 7-7.20 pace
Weds: 6 miles (inc intervals typically through sept-Dec 10-6 x 2-5 min efforts at anything from 3k-10k pace with 90 sec recoveries)
Thurs: Easy 5 miles at 7-7.20 pace
Fri: steady 6-7 miles with 4-5 at 5.45-6 min pace
Sun: 10-13 Miles off road at 7 min pace through the winter but will include 4-5 miles at 6-6.20 pace in the summer.
Through the summer I did 3 quality sessions a week but these were shorter more anearobic efforts tailored to shorter track races and i recovered more quickly.
I am hoping to get down to 33 mins over the next 4-6 months, I won't be including any more quality sessions as I simply don't recover quickly enough and find it impacts upon other sessions. I plan to add a 4 mile morning run 3 times a week, build the longer run up to 16 miles and the steady runs to 8-10 miles.