I tried the horse pad and while it works really well and is very affordable, I was not happy with the slightly musky sheep odour that it has, and which is released by pressing. The wool felt is not as dense as that of the pads sold for quilters, and is a bit rougher as well...so I am still on the hunt for yardage of felted wool similar in quality to the stuff you find in the pressing pads in quilt shops. I have a 3' x4' pressing table I want completely covered!
On the topic of flat seams with no pressed ridge from the fabric in the seam allowance, take a look at this video from Margaret Leuwen (love her tutorials), the pressing sticks are on my to-get list!
https://www.youtube.com/watch?v=_97-KDq5IXU