I'm actually "OK" with the hiss ... but the one sided "presentation" is causing me head aches.
I actually have a lot of experience with this issue (Studio2). You will typically see this with cheaper ANC implementations, for which there are plenty. I'm a perfectionist, so this REALLY bothered me.
This issue was present on the Studio2s as well, and after literally buying and returning over a 15 (yes, over 15) from various retailers (I got banned at Best Buy), I can say it will vary from headphone to headphone. Some, had an even presentation, while MOST did not (to varying degrees), which you can further test with the side-tone feature when using your phone as a voice recorder (tests the mic as well). SIDE NOTE: You will probably notice one of the adjustment sliders is much looser than the other. While most people don't really notice or care, again, as a perfectionist, it bothers me. I feel it is a quality issue and representative of the care (or lack thereof) they take in their fabrication processes.
The Studio2 & Studio3 are a consumer-level headphone, with average materials, build quality, and "Fun" sound. I eventually returned my Studio2s and just went with the B&W P7 Wireless as my daily driver, since I don't need ANC on a daily basis. For travel, I use my Bose QC 35, which is totally comfortable for long trips and sounds decent enough. I am really looking at getting the new Sony 1000X MKII, which I test drove and really liked. It sounds great and very similar with ANC on and ANC off. You do NOT get an uneven presentation with the ANC and the Sony app is really nice to EQ the sound to your preference (which saves it directly into the headphones). The app essentially controls the on-board DSP vs. post-signal processing like you'll get in many of the third party EQ apps. ANC is also on-par with Bose, but contrary to popular opinion, I still think Bose has a bit better ANC overall, but it's REALLY close; the Sony sounds much better IMO.
Beats definitely has its place and I find the Solo3 (on sale, sub $200) to be a decent headphone for the gym and general use. The Studio3 SHOULD be better, but they just went with the same formula as the Studio2 and just upgraded it vs. a ground-up rebuild.
If you're spending $349 (I assume) on the Beats Studio3, I say return it and get the Sony 1000X MKII instead. Except for the W-1 chip, Apple really hasn't brought Beats up to the standard of their other products, all of which are basically leaders in their own respective classes.