@lanx0003 I've never used the Ultra add-on.. which I'm glad you mentioned it as I should order one. I do think they need an extra volt to operate. But my Sbooster BOTW MKii does have an extra volt & half to play with. If the Ultra can improve on the Sbooster for $100 that's a good deal in my opinion.
As far as the Elite & Sbooster differences I would just say on the things I've tried them on the differences weren't huge. I may have had a preference of one over the other depending on the device but it would be easy for me to understand if someone else preferred the other PS. Personally I would normally recommend to always get a LPS. But the IFI's are cheap & I think they do a good job. The X being a decent piece to hold one off til a better investment can be made. I have been informed that LPS do a better job on components with an analog stage in use. It's not something I've experimented deeply with yet.
Thanks for the specs on the Ultra add-on!