There is Chicago Pneumatic (good stuff, in general) and Central Pneumatic (Harbor Freight brand, OK for some things, not for others). The Central Pneumatic name was chosen by HF to fool folks into thinking they were buying the good stuff.
Rivet guns come in 2 basic designs: Chicago Pneumatic and copies thereof and Ingersoll Rand and there may be some copies of it. Most clones are of the CP and parts of the clones are often interchangeable with the CP--Avery's are as are some from ACS. Both CHICAGO Pneumatic and IR are good guns.
At this point, I have not seen any info on the HF gun.
If it is the price that interests you, then I suggest you buy the real deal thru Ebay. There is an IR right now with 2 bids on it at $10.50 (it will probably go for somewhere north of $75), another with a "buy it now" price of $89.75 (looks like it has had a lot of use). There are some APT's, Jiffy's and others, mostly CP clones. Opportunities change daily. A good gun will drive millions of rivets before it dies; I would buy used before buying a Harbor Freight gun that has no reports on it.
I have both an IR AVC12 and a CP 3X. I prefer the IR; it hits a little harder and the trigger control is better, but it is a little longer than the CP and there was a place where I needed a shorter gun, so I used the CP. It's also a case of what you are used to and if I had started with the CP I might prefer it.