In terms of his albums as a leader, I only have the two LPs shown above: Invitation and Glowing. I prefer Invitation slightly. It's a classic tenor-plus-rhythm date -- and Mickey Tucker's presence is always a plus. BTW, don't expect anything mind-blowing -- but they are both enjoyable, solid jazz records.
As for his sideman work, I would recommend these (very underrated, IMO) Art Blakey albums, which also feature James Williams and Bobby Watson along with Schnitter:
- In This Korner (Concord)
- In My Prime, Vol. 1 (Timeless)
- In My Prime, Vol. 2 (Timeless)
Schnitter's work on Richard "Groove" Holmes' Shippin' Out (Muse) is also excellent.
I don't have any of his more recent stuff.
Hope that helps.