so first off I just wanted to say that asking about a product at a competitors site is probably not the best place
I guess that the first thing I wanted to address was the warranty. I have a CZInfrared (Comfort Zone) 1500 and I have been pretty happy with it and with the warranty. Its worked well but I was carrying the heater downstairs to dry out the bathroom after an unfortunate mess and dropped it but stopped it from continuing down the stairs by catching the cord... my point is that about a day later I noticed that it didn't seem as hot. Since I didn't keep my receipt/contact info from the distributor I called the manufactures # that was part of the owners manual. The manufacturer took care of my issue with straight away by offering to send out a set of bulbs or have the unit picked up or a third option of offering to send a voucher and the bulbs so a local repair man could repair it if I felt uncomfortable. Being competent I took the self service route and replaced the bulb myself. It was easy and gave me a chance to see how it was put together. A good build I have to say. After troubleshooting and offering to send out my part they advised me they are happy to help and that I can also contact my distributor for in person help in the future.
As far as the plastic comments its only the outside case thats plastic and the heating portion is enclosed in a full metal frame and if anything where as plastic may melt its less likely to catch fire than wood. Also most all of theses units put out about the same BTU's regardless of the # of bulbs. The bulbs in the comfortzone have a heat exchanger built into them that actually looked kinda cool like a mid evil weapon. My understanding is the biggest benefit is the infrared heat since it heats a whole lot better than my 700/1500w coil heater I had bought to heat my bathroom.