I am one of those that will stand up (again and again) for Vortex......and I sell them, as well as Leupold, Burris, Sig, Leica, Zeiss, Swaro, Kahles, Nightforce and a few more. There are a few things to note.
1. If you think that Leupold optics aren't Asian (most probably Chinese or Filipino) you are flat wrong. They are disingenuous about their descriptions of their products and are NOT transparent about their sourcing AT ALL. Look on every Vortex scope and you will see where they are made. Generally the lower end scopes (Crossfire and Diamondback) are Chinese, Viper and midlines are Filipino, the Razors are Japanese and the AMG line is completely US made along with ALL of the military components they were just awarded contracts for (remember they are a Vet owned, start up in Wisconsin). NONE of the commercially available Leupold products are made with US optics...period.
2. Comparing Diamondbacks to VX3s or above is like comparing a Toyota to Mercedes. The cheapest retail line of Leupolds, the very mediocre VX Freedom (undeniably Chinese), is priced at the same point where you can get into a Viper- $299. Looking at features available on the scopes is another point. The first Leupold with paralax adjustment is about $550- you get that on Vortex scopes at less than half that....and if you are shooting any distance at all you should care about paralax.
3. Complain about having to use service if you want, but TRY and get attention or a straight answer from Leupold in the same manner. Good luck with that (remember that they warranty only defects-not damage, and anything electronic get 2 years and not a DAY longer.) Here is my personal knowledge of the difference. Before our store opened we in the gun dept went through about 4 months of training. This consisted of all of the vendors being given the opportunity to come and train us on their products. Vortex sent a two man team for a day and a half or training. First a half day of classroom on the different lines. Then a full day of shooting. For this they rented a private ranch with an 1100 yd range, brought a trailer full of rifles, scopes, rangefinders, spotting scopes and an outfitted gunsmithing bench for adjustments. Leupold chose to take a 3 hours block of in store classroom training. The store paid for the entire gun staff to be there for the allotted time. The Leupold rep showed up an hour late without the courtesy of even a call. When he DID show he dumped a box full of swag (shirs, stickers, coozies, etc) on a table, said "Hey guys, we have some great stuff, check out the website" Turned, showed us his back, and was off......seriously. If we have an issue with either supplier it is either call Vortex and get a person immediately on the phone (worst case scenario next business day) or call Leupold to get voicemail/email and wait....and wait. Literal disinterest. I am NOT saying there is anything wrong with their products, but company attitude and attention is a serious component of satisfaction.
4. This may break some hearts but it is a fact that folks really should get their head around no matter what optic you choose. If you want to get long term, top flight, performance out of your rifle you should be spending AT LEAST in the same cost neighborhood on your optic as you are on your rifle. Most modern rifles can shoot better objectively than 95% of shooters. Optics systems (including mounting and rings) are a HUGE component of performance. If you are trusting your hunt to a $250 scope and crappy rings you should take a hard look at that.
I am not going tell folks what to buy, as a matter of fact I make MORE money from selling Leupolds than Vortex products due to the inherent cost difference. Neither am I going to say that Vortex is my favorite line of optics. For my purposes (mostly hunting), and what I have access to, that would go Swaro, Leica, Zeiss, Vortex, Leupold and Burris. This is a value and performance based list based on MY observations and needs. As a matter of fact, right now we have GREAT sales on both Leica and Zeiss scopes for under $1000 with German and Japanese glass respectively. Pick what you want, but look at things from a bit wider view, check out all the options and do research. BTW, you can get into Swaro Z3s for the same price as some VX3s and Z5s for the price of VX5s.......think about that. Asian glass from Leupold versus Austrian glass with Swaro with the Z3 and Z5 having that glass AND being assembled in the US .....IJS......