I've got a 3-15x44 with Impact 29 reticle and absolutely love it.
I have a non HD VX6 3-18x44 and find the glass on the VX5HD to be a slight improvment.
The glass is great, super crisp and haven't noticed any edge distortion or fish eye.
The FOV is great and a really forgiving eye box, I have a Vortex HST 4-16 and a PST 4-16 and the eye box on the VX5 is 100x better, not fussy at all.
I haven't actually done a tracking test but I shot a 22lr rifle match this weekend and with a 60yd zero was dialing out to 172yds and back and was spot on, have also shot back and forth between 60yds, 100yds, 130yds, 150yds then back down again and was dialing perfectly.
The turrets aren't mushy at all, they are not like a Nightforce but they are positive and audible.
After the match I shot I was having a play with a few different rifles, one having a Athlon Ares BTR 2.5-15 another with a Kahles 624i and another a Zeiss Conquest 4.5-14, apart from the Khales which was fantastic, I felt the VX5 had the best glass.
The VX5 was heaps brighter than the Zeiss and far better FOV, and I felt was a lot brighter than the Athlon and crisper too.
Compared to any of the Vortex HST or PST Gen 1s I've used, the VX5 is hands down far better glass.
I really like the Impact 29 reticle, it's my first Christmas tree style reticle and I was worried it'd be to busy, but it's fine enough you barely even notice it's there unless you are using it. The open center is nice for shooting small targets also.
I was just using my 22lr to test this scope before putting it on my 223, but I can't bear the thought of putting a lesser scope back on, so will likely be buying another for my 223. My Vortex HST will be getting the boot in the near future, whilst it has done me well, the glass is abysmal compared to the newer scopes coming to the market.