My red mist SSP is the one I use all the time. My tank was out of date & did not have the more modern triangular shaped knob that indicates it has the modern safety feature that prevents overfilling. However, it did have a sticker on it indicating that it had such safety feature. if you take it to places that employ low wage employees to refill tanks, they won't refill a tank that is expired, they usually have nobody that can recertify them, and they won't fill one without the somewhat triangular shaped knob. However, at many of the smaller mom & pop places, the owner (or someone) can recertify them. A local place near me will recertify a tank free if you fill it up there, so it cost me about $5 and change to get it filled AND recertified. Additionally, he was accepted the sticker and even pointed out that I might want to bring it back to him because a lot of other places will just refuse to refill it because it doesn't have the triangular knob, since that is what they are told is needed.
Frankly, I never have even tried the gas assist. I just use my chimney anyway. With respect to the comments about the table, as noted the SSP has a table with a lid that has to be opened to get to the the gas assist, whereas the other models have things you operate on the side. On the plus side, they are more protected being under the table top (you can probably figure out why I know that).
Another negative some mention is the handle that is on the top so you can lift the table (lid) and you have to pay attention to where you set down a platter (or whatever) on the table so that the handle doesn't cause your platter to tilt. I don't find that a huge problem, just set things down to one side of it. On the plus side, the stainless steel tops don't crack or get badly discolored like the fiberglass ones tend to. Even the newer metal ones that are painted black can have problems. Seen a pic or two noting issues on ones that were not very old & I saw one for sale locally that had gotten rather bad looking (like really bad) for not being very old.
Basically, there are pluses & minuses to each type. Based on comments from others in Canada, I'd keep an eye out for ones across the border, that are within striking distance.
You might want to look at whether there are any weird customs duties for used equipment. In many countries, the dollar value of something has to be higher than a set level before duties are imposed, so you might look at that too. I have some relatives in Europe that I'm guessing would just strap it to the roof of their car & then say "This old thing? I brought it me when I left the country to go..." on a picnic, camping, or whatnot.