Henro, I wish my satisfaction quotent with Thermal was an isolated event, but it isn't. In my area, I know of several people who have shared similar experiences.
As you say, when manufacturers go belly up, parts of their business are often bought up by other manufacturers, much as we have seen old line manufacturers absorbed into large holding companys in the past few years. A prime example is that Hobart and Miller are both owned by the same holding company. This resulted in Hobart discontinuing support of a lot of older equipment and selling off of several product lines, to satisfy the government. At least 1 of Hobart's lines was sold to Thermal, where it was revised to become compatible with Thermal's design criteria.
We've also seen Homelite go thru being owned by Textron, then John Deer, and now Royobi, and this has left trainloads of Homelite equipment abandoned in terms of service parts.
From my standpoint, with over 40 years of welding under my belt, I don't like it when a machine is no longer supported with replacement parts. I also fail to understand the enfatuation with NEW, and STATE of THE ART welders. I can fire up a 50 year old Purox torch, or a 50 year old P&H machine in my shop and weld with them quite well. I've said it more times than I can count, but, I'll say it again, the weld is made by the weldOr behind the mask, and not the welder he runs. I've still got a Lincoln toumbstone I bought in 1963 that I can lay down a better weld with than a lot of guys can with the new machines.
Things like square wave and inverters are nice, but, machines have to pay for themselves, or they are money down the drain. Miller, Lincoln, Hobart and even Esab, did not design and build machines like the Dynasty series for the home workshop, they were designed and built for production welding, 24/7.
http://www.weldreality.com/default2.htm clearly points out that most of the money expended on fancy machines in industrial situations is wasted, because the people involved in selecting process, and buying machines aren't weldOrs.
For a man operating a small shop, inverters and square wave TIG are overkill, and he will need repair parts down the road. There have already been postings about keypad problems on these machines. From where I sit, I'm fairly confident the manufacturers will have obsoleted these current machines in 5 years with a new generation, and while most of the machines in production situations will be writted off and cost effective to replace, the backyard shop operator and his need for parts support won't be economicly justifiable for the manufacturer to continue making parts for.
Manufacturers like Lincoln, Miller and Hobart, possibly Esab, will be there with parts for 10 years, probably. Thermal, well, if they get sold off, it will be like trying to get parts for your Textron generation Homelite saw.