It also gives me a target for the large-and-in-charge amp with 4-pin XLR output that I've been mumbling about. Thanks.
Remember, you need 120V discrete OpAmps to compete with them, because OpAmps running on low supply rails are bad mhhkayy. And you also need to give the THD+N for your headphone output into a 100kOhm load. If they are trying to sell to enthusiasts and professionals alike, why do they need to do this stuff? I guess because the so called "audio professionals" that are so regularly attested with substantial knowledge of analogue electronics in reality are pretty vulnerable to this kind of "facts". Or maybe they market to them via the extensive set of features that consumers don't actually need and the 120V OpAmp stuff is mainly targeted at the latter. However, not a fan, RME does that better. By that I mean finding the line between ornate language regularly used in audio marketing and sticking to the actual facts.
Needless to say that I think you can and probably will do better than SPL, both in most performance figures of interest as well as marketing. Maybe I'll be tempted to upgrade from the HP-1. Will there also be a questionnaire like for the HPA-1 or are you working with the data from the last one as well as customer requests you collected at the Expos you frequented? Will you target mainly consumers or also professionals?