Alpsman, I don't know anything about Promicrol but I get constantly great results with Delta 3200 in DDX. I'm sure there are finer films, the Neopan 1600 used to be one. But when it comes to contrast, nothing can beat the Delta 3200, IMO.
Lawrence, it's not my intention to find a better film than Delta 3200 - as to my needs, it's the best film at 1600, period - but a cheaper alternative that is not far behind. I would like to try the TMAX 400 and Microphen combo first. May I ask why you recommend me the undiluted D76 instead of the undiluted Microphen? Isn't the latter said to be a better developer for pushing?
Also, I thought it would be better to do less inversions if the goal is to keep the contrast down. If you didn't say anything, for 11 minutes, I would have tried 2 or 3 tank inversions every 2 minutes.