While I haven't seen a Slingshot bike in about 20 years, it looks like they still are in business (google them), but, like I said, this isn't a bike that is very common these days, and they were considered a bit funky back then. So, I don't know if it is a good buy. S&S couplers are a good and proven system, and by far the most popular among builders and retrofitters. I know nothing about Slingshot's system. If you can't even see it or ride it beforehand, my hunch is it is a bit of a risk to buy it. There is very little info about the bike on their web site, the top tube looks...weird, and there isn't a geo. chart or any info I can find about how the folding part works. The website seems to acknowledge it is a brand new thing, the folding aspect, so I can't imagine it is a proven system in real life yet. Yes, I agree it would be good to hear if anyone else has ridden one lately. If you like your current bike and it fits, and you have a good builder able to do the retrofit with the couplers, my inclination would be to recommend the retrofit.