I have a pro account with instant forward turned on. I'm having very inconsistent results with instant forward. Some messages forward instantly, others with a considerable ~10 minute delay and some messages don't arrive at my email inbox at all. Spam filtering is not the issue: my spam folder is empty and I have previously set up my email so that emails sent to Throttle-addresses skip spam detection.
It's very frustrating having to check my Reading List on the Throttle website just to make sure I haven't missed anything important.