My apologies as I'm unclear what version/model of the warmers you are looking for feedback on as Woodcraft and CH offer three different versions/models.
My experience is that Woodcraft and CH offer high quality products and really great customer service as well. I had the highest level Woodcraft warmers/bakers a few years back and unfortunately had several problems with them. The great thing was that Woodcraft took great care of me each and every time. Meaning they worked to make it right, by standing behind the product.
Unfortunately, the problems became too much of a liability (not having warmers when I needed them) and I moved over to CH digital (the highest version/model). I've had good experiences with CH digital warmers for over 3 years now. That is not to say I haven't had issues with the product (not all things are going to work 100% of the time), I have, but they also stand behind their product. In my experinece, the difference is that I've had fewer issues (time without warmers) with CH than I did with Woodcraft.
I'm sure there are others that may have had a different experience. The bottom line is that both company's offer quality products, excellent customer service and support the sport by being actively involved in the sport.
So, you really can't lose. Find the product that fits your needs best and go with it.
Just my .02 for ya!
Allen