Manfrotto panoheads are way too large and too heavy and too yesterday in design. Everybody who has ever owned one has sold it or wants to.
Precision360 have the worst service in the world and the most overpriced panoheads on the market. The most arrogant people in the industry (Google search complaints). Still, they are loved by their owners. That said, most have never own any other brand and purchased because they think money buys perfection. Really needs PTGui template for stitching (at least to get what they claim in their promotional speal).
Kaidan well I'll put my hand up. Their service to me was poor after buying a few panoheads and even when the owner (Jim Anders) publicly stated he would appease me he failed to even try. It simply was a whitewash job for the public. Simply not good enough in my book.
Nodal Ninja the one that hasn't been mentioned. Good product all round and well respected. Underlying their public perception is a company that from a business point of view you need to watch your back. Still, good product worth a mention and unless you are going into business with them all should be fine.
Panosaurus is a cheap plastic entry level panohead.
King Pano another plastic entry level panohead.
Jasper Engineering Single row and not suited to 360x180.
Agnos, supported us when nobody else bothered. Made affordable product and backed it up with good service even though they didn't speak English that well. Wide range, something for everybody.
Understand these are my personal findings, I have no control over what you purchase. I do though offer my opinion in good faith without financial reward and years of experience using pretty much all the brands listed either owning them or through borrowing them for evaluation from my tuition customers.