SWFA makes great stuff if you can get it. Hard to say what is going on with that company behind the scenes right now. The 3-9x is basically unobtainium unless it’s on the used market. The 3-15x is generally in stock along with the fixed 10x. And the 6x seems to show up occasionally. Since they changed their website, there is no way to get on a backorder list anymore. You just have to watch their site like watching paint dry.
But in terms of SWFA scopes, the fixed 6x mil-quad is my favorite for hunting. It’s cheap, reliable, and simple. You just cannot beat them for $300. The 3-9x comes second, only because it’s double the price. It has HD glass, which I don’t think is a big benefit. The zoom rings on mine are super tight, so I generally set them around 6x and leave them. The 6x and the 3-9 reticles are identical and I think they are among the best out there. Both scopes weigh about the same as well. The 6x has adjustable parallax which I set at 300 and never adjust. The 3-9x has fixed parallax. The 3-15 is my least favorite of the three. The biggest issue with it is the eye box, which is pretty unusable above 12x. The reticle is also subtly different in that the diamonds that serve as hash marks are not filled in. The result is that it’s a little more prone to fading out in complex backgrounds, but otherwise it’s the same. The scope is also bigger and heavier than the others, but you don’t get a lot of the benefits out of it due to the eye box limitations. None of these SWFA scopes have zero stops. You can add washers to them to create a stop, but I’ve not done that and it’s never been an issue for me. The SWFAs are tough, but ugly. The friggen turrents are way bigger than they need to be. But I really like them and hope the company doesn’t die.
I have not used the Maven, but it’s on another level above than the SWFAs. From what I’ve seen the reticle is as good or slightly better. Based on my experience with other Maven optics, the glass will be better. However I do not think that is a limiting factor for scopes. The durability appears to be similar to the SWFAs. The Maven is just a nicer overall scope. It has a zero stop and turrets that aren’t hugely oversized. The only downside is that it’s a little porky at 26 oz. That said, it’s among the best scopes available in its class. Availability-wise, this scope is a backorder situation, but they are coming out with them every few months.
Finally, I’ll give an opinion. I don’t care for high power scopes with magnification above 10x. While they might be nice at the range, the high magnification makes it slower to get on target for the initial shot, harder to spot your impacts, and slower to get back on for follow-up shots. I’ve also never found magnifications in the 6-10x range to be a limitation in field conditions. You do not need higher magnification for hunting out to 600 and even beyond.