I'm considering picking a few things up from Discotek. How is their quality overall?
They tend to be pretty good, though they have a few poor releases (Teyandee and Blue Sub No. 6 BD) and rarely do BDs of full series since they're pretty small scale.
>mfw Red Jacket soon
Adding to that, dealing with Toei can sometimes lead to problems (see the initial release for the Fist of the North Star movie).
Their Mazinger sets are certainly good.
Absolutely nothing. Discotek releases are either bare bones or packed with extras, there's no in-between. Their picture quality and subtitles are usually excellent though, with only a few notable exceptions.