I have the Peet Shoe Dryer. I received it as a Christmas present this year so I haven't used it a lot, but here's my experience with it.
It is rather large for travelling, but can be done since the base is actually two pieces and the drying pipes can be pulled apart (leaving 4 pieces in total). Apparently you can buy a travel bag to pack it in, but I haven't found it available in Canada.
The unit is all plastic except for the heating elements. It appears to be durable enough for drying ski boots, since the unit sits on the ground and you have to mount the boots or the boot liners on top. The heating elements produce very gentle heat, which rises into the pipes naturally (no fan that I can hear or see) and into the boots. The heat is not that hot like a hairdryer but it does build up in the liner and eventually dries the boot. It has a 25 year warranty
My first use with the dryer I put both ski boots on the dryer and left them over night for about 8 hours. I didn't realize that it used heat to dry, so I left my custom insoles in the boots. In the morning I checked the boots and they were dry. I took the insoles out and noticed that the heat of the dryer and the weight of the ski boots put a little notch into each insole (from where the dryer touched the insole). It didn't ruin the insoles, but the notches are still there after 3 weeks.
After the insole experience I dry by taking the liners out of the boot and the insoles out of the liners, and just dry the liners. Since then I have nothing but dry liners and dry shoes. I have no complaints. But I do have a concern. Since it uses heat to dry and I have Lange FR Comp 120's with heat moldable liners I'm not so sure how good the dryer is on the liners. So far the liners still feel comfortable and molded to my feet, but I'm not sure whether they'll break down quicker over time.
I bought my sister the Thermic boot dryer for Christmas which doesn't use any heat to dry but uses room air. It is much more compact than the Peet Shoe Dryer. I'll let you know how she likes it after she uses it.