I'll try and illustrate why I think pacemakers are a good thing and why the faster they are the more quickly you can determine how good a horse is.
Typical pacemaker run for me. Note the final split time. 2.05:8 - 1.52:0 = 13.8s
As slow a race as you will find at the start. Note the final split times. 2.05:9 - 1.54:7 = 11.2s
Another off pace race. Not as slow as the above but note the final split times for the top two horses.
2.05:9-1.54:1 = 11.8s
2.05:9- 154.8 = 11.1s
Here is the point. For any horse on any course I believe there is a fastest time it can run as dictated by the game mechanics. Each of those horses with the exception of the pacemakers are capable of running 2.05:9 or better at Newmarket. Without a pacemaker they still achieve it but it takes MANY more attempts to find out what they can achieve. With fast pacemakers, you'll see results more like the first. Without pace the horses need to run faster splits at the end. But there is more variability as it is rarer to run those fast splits. The faster pace simply allows them to show what times they can achieve with less testing which means you're more efficiently finding the best horses. Slower pacemakers = greater variability in times in my experience, hence why I use two/three pacemakers in each race I run.
Feel free to do whatever you wish
but fast pacemakers is a cornerstone of my breeding plan as it allows me to spend less time finding the best horses and getting more breeding in 
