Was able to attend 2+ games against the Missions. After digesting it all, I figured I got a glimpse of the transition to Luhnow's system. The position players I saw were about 50/50 Luhnow and pre-Luhnow, but even the pre-Luhnow ones have had plenty of time now under his system. Basic observations were similar to what I had read:
Much greater patience at the plate. Almost every batter sees at least 3 pitches and few swing at the first pitch;
Not too many ABs where the hitter is chasing bad pitches;
Many of the hitters might let a cookie pass by on their way deep into counts;
Most guys have decent contact skills. Not a lot of swing and miss, but given that they get into a lot of deep counts, the Ks will come; and
Most of the Luhnow guys seem to lack loud tools, but on the flip side, they don't have glaring weaknesses either. All have a nice balance of less-loud tools.
Overall, through the course of the games, I came away feeling better about the descriptions above than I felt when I arrived. In general, I love to see a hitter jump on the most hittable pitch they will see, but realize that few do that and that ultimately, the skills they now demonstrate (patience and pitch recognition) might be necessary precursors to the higher level skill.
On the pitching side, only Ballew really impressed, but I obviously caught Cruz on the wrong night. I think I expected something else from him, but it looks like his success depends on commanding multiple pitches well, ala Keuchel and Obie, and not on stuff alone. Without that command, success is unlikely.
Individual observations:
Fontana - is what I assumed, but slightly better. Can handle SS, but arm is marginal. Patient, maybe too patient at the plate, but can make contact and is more than a slappy bat.
Aplin - looked better the more I saw. Looked like a solid fielder in right, had good ABs and gap power.
Tucker - has that flat, line drive swing, but will have to hit better to provide real value, IMO
Deshields - it is hard for me to erase everything I have read about him, both in his skills what it takes to maximize those skills. He misplayed one at the wall, but he reads the ball well/gets good jumps and his routes are fine. In other words, he can handle the position, but exceeding at it seems up in the air. He has good pitch recognition and some pop.
Nash - would love to see him stay healthy to see what he can do. I have heard about his power and don't doubt it. He put one out to left on a slider that he didn't even time or turn well on.
Mier - his swing looks better to me. I realize the results aren't there, but he looked better.
Garcia - Always impresses me. Good contact skills and seems to handle the position defensively.
All in all, they all seemed like solid players and with further improvements, some will have a future on the Astros. If I had to put money on the ones I saw, I'd bet Aplin, Fontana, Deshields and Ballew have the best chance to succeed.