Just FYI:

I'm using Numinix's 1.11.1 (he just posted 1.11.2 with a bug fix for Availability on 10-5-2011) with Zencart 1.3.8a patched for UTF-8 and am not having any problems (knocks on wood).

Numinix added a switch for the sanitizer so you can turn it off (default). They may actually make it "safe" for non-utf-8 stores. But you better test it first!

Only issues I've noticed is with the Security Key and my Cron jobs. I coded out the Security Key last time, and probably will again if I can't get it working this time.

3,000 products submitted and accepted fine.

SIDE NOTE: If you want to add your "google products category" to your feed for every product, it's actually pretty 'easy'.... I added that functionality in about 20 minutes to the base feeder (not elegant, mind you), then modded my EasyPopulate4 (beta!) to let me upload gpc's for each item by just adding a new field to the products database.