OK so I just picked Hal and used him in an RS game, I also was facing Hal for the first time, so quick blurb on what I think of him if that'll help anyone
It was a WC game, my opponent had a 15-8 record coming in, so they're decent competition and it was AS difficulty. I won 7-1 and it went the full nine. five of my runs were off his newhouser, he scored zero on mine
Hal's velocity is great, he throws really hard (FB can hit 100) and the difference between his FB and change/any offspeed really is great. It makes it hard to hit against him and I struck out eight times in seven innings against him which is above average for me, I basically just sat on offspeed or FB the entire game, couldn't hit both simultaneously. His h9 and k9 are also good. I had a few hits die on the track because of them
His control was what I was worried about. On the 4seam it wasn't an issue for me, especially once I got his confidence up in the third he located it really well considering the game state and compared to other pitchers. His change was also fairly easy to locate. The curve was impossible to hit your spots with though, I gave up throwing it after the 3rd and basically just used the slider in its place since they both have similar movement. I didn't use the 2seam.
His delivery is so-so imo, not bad, but not glitchy either. The only other thing that caught my eye was stamina. My opponent threw 110 pitches with him and was still good on energy, I only used 80 in 7 innings and he had over half his bar when I pulled him. With the way it's setup this year, I think his crazy stamina gives you a legitimate opportunity to abuse the system and throw him often if you manage it well which could be a big advantage. It's really hard for me to compare him having only seen an inning of Kluber this year and having not used the others, but after that game I'm happy with my pick. He's not broken like Kershaw was last year or anything (granted with the current meta it's hard for any pitcher to dominate), but he's a very good pitcher and checks all the boxes for me