Well lets hear about it.
I'm currently using STS. Just started with them about 2 months ago so I cant give any long term feedback, but so far so good.
STS inks haven't really caught on for as much as they've promoted themselves. Most user testimonials, from the people I've talked to, are not good when their inks are used in demanding applications. Short run, short life, junk work then sure any ink will do. But users trying to match standards of stretchability or longevity for wraps, industrial decals, billboards, etc. No way. Not even close.
BigFishDM is a distributor - I don't know him, but you don't get to that point without spending a lot of time neck-deep in the industry. Just like I have worked through most OEM and aftermarket ink chemistry, that experience is worth something. I'm sure he's a distributor for the ink solution he is recommending - and if he has tested and vouches for it then he should sell it to his customers, not give that experienced information away for free!
That all said, I'm the opposite of a latex nerd LOL - I dislike latex, in general, for many reasons. Along those lines ... you have to ask yourself if it's worth expending the effort necessary to move to aftermarket inks, heads, service End of Life, support End of Life, etc. HP is infamous for cutting off software, hardware, and technical support on machines like a guillotine - way harder than any other industrial manufacturer I've ever seen. Their "support" is all based out of India now. That printer is slowwwww, consumables are high - cost per square has never been HP's strong suit. Why not replace it with something new? I mean, you can get entry level R2R sub-64" machines for $200 a month installed with more speed, better quality, and half the ink cost TODAY. I think a lot of people let the idea of "it's already paid for" way overpower the math of what they're literally losing on their old machine. And make no mistake: HP is not known for being cheap when you appropriately calculate TCO.