I have 2x of those, plus 2x external VFOs. Around here some place is a thread I started which gets into some modifications. I have DDS PTO replacements to evaluate and was looking at fitting Omni V/VI/Paragon IF Units, taking advantage of some additional filtering. May get around to it...may sell them before and tinker with something else.
Some time I need to look into plumbing the shack for 220v so I can run my Herc-IIs. I currently have three - two operational; one in need of repair - along with two 9420 supplies. An idea for the future is to run my two Paragon IIs, the Herc-IIs and matching 253 tuners from a solar/wind/battery storage setup. Also have an Omni V, Omni VI and one more 253 (in need of repair) that I could set up as a 3rd station.Hercules II: I just "segregated" the DC cable into three (two high current inputs for each RF pallet plus a low current input for control) so I can use two independent 40A power supplies. I haven't tried that yet, but it should work.
One of my "Mods and Repairs" threads showcased the Omni VI with a blue (instead of the stock green) display. I'd love to find 7-segment cyan LEDs to make it match the appearance of the Omni V, but may end up going with white plus some blue filter material instead.