Again speaking personally what has made a difference for me to get from 44m to just above 40 (haven't cracked the 40 yet, but now definitely feel that I could) is introducing some speed work sessions. These have taken a mixture of track sessions 10-12 400m repeats at 90secs or slightly quicker with a 100m walking recovery, or a loop of about 700m on the road with a 60-75 sec walking recovery repeated 6-8 times.
What you could also do is incorporate some speed work into your regular paced run, say going for 1 or 2 Km at your desired speed to break the 45min barrier, so that would be something like 4m25 for a kilometre.
I also made sure that I was regularly doing runs over the 10k distance so a 'normal' run would be 7-8.5 miles, I didn't get any time to do even longer slower runs but that also seems to help as well, as a lot of it is about how much time you've spent on your feet...
Horizon Elite 507 gets my vote - Had one for 6 years, good piece of kit. The company completely replaced the machine 6 months ago as the incline motor separated from the frame - thank goodness for the lifetime frame and motor guarantee. The company was very good in dealing with this and I had a replacement in no time, otherwise no problems with this machine. It cost £999 when I bought it, not sure what it is now, got it from Fitness Superstore online, they also were good to deal with. Just my 2 cents input for what it's worth.
Been drinking full fat milk all my life and ain't about to stop now I'm 40 odd. I eat real food, proper food, don't agree with modifying food that we have been consuming for generations milk, butter, cheese, eggs etc just to take out the natural fat. You want to drink skimmed milk feel free, leave the real milk for the rest of us.
In the office where I work just now we have shared fridges - I only ever buy blue milk and I am in the great minority, consequently my milk never gets pinched (side benefit!), I constantly get comments from one lard boy or another saying ooh you're drinking the bad stuff.... Half an hour later they will be the one at the coke machine getting Diet Coke obviously as that's better for you (don't get me started on that one) and washing it down with a bar of chocolate.
Eat right and exercise right, the rest takes care of itself in my opinion.......................