TL;DR: I'm happy with the service I received.
After filling out the form and sending the bitcoin requested, I received an automated email confirming my order. There was silence for a while after that, so I emailed Ivan around three days later and received an apology shortly after stating that he'd been having issues with his email and hadn't received the order notification.
Four days after that, I received an email (which went straight to my spam folder, so it's good thing I'd been checking there) with eight proposed logo designs. After a few days of consideration I chose the one I liked best. Two days later I received an email with two zip files and a PDF. The PDF was a single-page "corporate identity" guideline, with hex codes for the colors used in the logo and the name of the font, as well as various renderings of the logo: buttons, an app icon, a vertically-oriented logo, a horizontally-oriented logo, and a "general use" logo. One of the zip files contained various 3D renderings of the logo: the app icon rendered in brushed metal, the "general use" logo rendered in brushed-metal-on-leather, the "general use" logo rendered in embossed-foil-on-paper, and the vertical logo on a piece of paper with a suggested mission statement underneath, hung from string and paper clamps in front of a white wall. The other zip file contained the logos and the app icon from the corporate identity PDF as PNGs, plus a white-on-transparent rendering of the "general use" logo. All the PNGs in that zip file were 1000 pixels on their longest side.
You can see the logo I chose up on my placeholder website at http://liftofflabs.co/
Thanks for the review!