My comment is not directly related to the angle of the slant (I'm an S1 owner). But I must talk about QC at ATT.
I own the 5 piece Kronos + Slant. I have no problems with the original items purchased.
But I purchased an additional Kronos handle and the machining on the thread was so poor I couldn't tighten it to my R1. (I use 2 heads; the R1 sometimes under the nose). I sent back the Kronos handle to Stan 10 days ago and have been disappointed by the follow up. I've received no replacement and very little help. I'm leaving on vacation in 4 days and I'll have no additional Kronos setup to take on my travels.
Im still a huge ATT fan. I hope sincerely my problems are isolated.
I noticed your comment got glanced over by Stan... lol, not the most communicative guy I've come across, good product but the communication needs work. I hate waiting days for an answer.