I have the iFi (first one)
amazing for the price point
crank the volume there is slight noise, overall pleasant presentation, leaning towards the bright side.
Have not heard any of the phono pres in your list.
I do use the MS Nova Phonomena I with the battery. I also use the SoundSmith Aida which is a cart that uses the BO MMC design principles. It's an amazing combo. I don't think you would be disappointed with the MS Phonomea. It is very neutral and transparent. Nice sound stage and very good dynamics. I can also say that without the battery on there is very little difference. Maybe a bit quieter but talking a very small amount. I have heard some phono pres at double the price that barely edge the Nova out or are just different but not really "better"
I had the ifitube buffer and thought it was good performance for the buck.
Hi, Vista phono here. Unfortunately, I can't give a first hand comparison to the others. "They" say the Lounge Audio MM stage is the only competition for the money.
I bought it as a tool for checking MM loading options. It reminds me of my AHT with plug-in resistors, and I'm really pleased with the performance. The sound is neutral with good resolution - just what I was looking for.
It comes with 47K and 150pF as the standard load and you install resistors in parallel for a lower value, but you can order it however you want. They'll put in whatever capacitance you want and you can order it with no native resistance. Then, whatever value you install becomes the resistance. Mine has no native capacitance. They put in another set of sockets and I load caps also. It's a bit fiddly that way, but I have the flexibility for many different carts.
Gain is adjustable from 40 to 70dB. Currently I'm running a Stanton 980LZ at 1.2K with 60dB gain.
It's tiny - a few inches long. I put a weight on top. The only caveat is there is no ground lug. You can float the ground or if there is noise, connect it to another component. It hasn't been a problem.