This is in response to OP's post.
I still own the Sunfire True Sub Junior which I bought way back in 2002! it is still working great. I have tried SVS SB12 (last year model), HSU STF-2, Emotiva Ultra 10 and 12 and I was not impressed by any of them as they just did not dig deeper than my tiny Sunfire. The only plus side was that those subs came with a 2 prong plug so they did not have the constant hum I get with my Sunfire. It is not audible to me away from the sub but the ground loop is going to be a potential problem when you have a 3-prong plug. May be that is one reason why the current subs dont use a 3-prong plug? I did get a very loud hum with my Boston Acoustic Duo (clock radio) and it only had a 2 prong plug! I wont pretend like I am an expert in electrical stuff. So I am not sure if only a 3-prong plug can cause the ground loop hum. If so then the hum I heard on my Boston Duo was something else? It does seem to go down to 60Hz considering the amount of bass I got from those tiny speakers.
But the general opinion here is that the Sunfire subs have amp issues. Note that back in 2002, outsourcing was not the norm. Now pretty much anything is made in China and so reliability is of great concern. Other brands like Epik and ED are/were facing amp issues and that is probably reason for a company to go out of business.
So given the reliability issues associated with anything made in China, I would take the 5 yr warranty to 1yr limited warranty and extra repair cost. if you really want low end extension and dont mind the weight, try ported models by Outlaw or HSU as they are very reasonably priced. It is a lot easier to deal with small companies when there is an issue but that may not always be the trend given the customer support by ED. I have not heard about bad customer support by companies like SVS, HSU, Outlaw etc.