Not him but that's my OC. It's fucking amazing. I've played the living shit out of Blood and I can't tell anything off gameplay wise. First time I ever tried it I immediately felt right at home, albeit with much better performance/framerate/mouse control. I bait the exact same behaviours out of enemies, my guns feel exactly the same, everything feels the same. I even notice the same tiny weird idioscyncracies Blood has while playing GDX; the kind that are so minute that I wouldn't have even thought of them unless I was playing the game and noticing them happening. The only thing I found different in the version I tried is that the Life Leech has similar behaviour to an earlier retail release 1.0, where it gives you life when used against enemies.
It's a great port and I'm never going back to DOSBox, which for me has gross performance drops and suffers from variable input lag. Meanwhile I play GDX at a rock solid 120hz. Apparently BGDX doesn't desync with Blood demos from '97 which is a testament to its accuracy. Hell you can even use your save games interchangeably from GDX and the original release. Even running fan addons like Death Wish, French Meat etc is now super easy, instead of jumping through all the annoying hoops you had to go through in the past to get them working with DOSBox.
I really wasn't expecting it to be so good, and was fully expecting to come across something that didn't feel right gameplay wise, but it just didn't happen. There are rare visual clipping issues and the polymost renderer used has washed out colours/less atmospheric shading compared to the original software render but that's it (polymost also has advantages however, like being a true 3D renderer so you don't get distortion when looking around, and of course GDX runs at much higher resolutions without slowdown and features true widescreen support). It's still in beta though so expect the visual glitches to be ironed out.