Two items regarding the use of the Mackie Control and Extenders: 1.If you download their Mackie Control for Pro Tools' User Guide and look on page 12 it says that bank switching causes the channels to jump over by 8 times the number of devices present. for example, if two Mackie Extenders are present in addition to the Mackie Control, the BANK buttons will jump 8 x 3 channels at a time. Well, apparently this is wrong. It took me about a day to get this straightened out with Mackie Tech. Supt., but the they tested a MC with one extender and it only jumps over 8 channels at a time, not 16 as the manual says, probably due to HUI protocol. Anyway, that's probably a very good thing since to change plugin parameters and send levels you have to do it from the Mackie Control by bank switching to the channel needed. So if, for example you needed to change a send level on channel 12 and bank switched the MC one time you would be at Ch. 25 on the left fader(in a 24-fader system where the bank switching worked like the manual says)and would have to "channel switch" to get over to Ch. 12. Lots of button pushing. I should know definitely in a couple of days, but I sure hope Mackie Tech. Supt. is right. 2.The faders have been upgraded from the ones in the HUI and are supposedly much more tolerant of grounding and humidity issues. I'll post if any strange things come up, but I've researched the heck out this before I purchased so hopefully there won't be any surprises, at least not bad ones.