OK guys, I am only interested in actual USER opinion on these films.
So far I have only used the ERA and Foma 100 on seperate occaisions, not together in a proper shoot-out.
The ERA you see on the auction site has box labels saying "Panchromatic Portrait Film". The contrast appears lower than normal, which is probably appropriate when exposing under studio flash or of you've got a Graflite that escaped the Star Wars treatment.

I am not sure about the Shanghai. I have yet to use some.
Any informed comment?

I have used the Foma. I have heard some bad stuff about it's reciprocity performance. The wide-angle on my 'Crown is a 4" Wide-Angle Rectilinear.
Typically used at f32 the lens cap is also the shutter. The speed drop may be an issue come the winter when I need a longer exposure.
I can't fault the contrast of the stuff so far but more research is obviously needed. The development time of the Foma 100 is near half the time as for FP4 in my usual soup of choice which is R09.

Please try and keep your comments strictly on your actual experiences of the films themselves.

Ilford FP4 is twice the price of the Foma 100 and pretty much three times the price of the ERA. This excludes shipping of course.

Foma 100: Thin base film, slips out of developing reels easily (Jobo2509n). Good in low to medium contrast lighting. In several high contrast lighting scenes the shadows were lost to blank film even though the metering and N developing would have had detail on Tri X, Tmax, Delta 100, or HP5+. Good for non critical snapshots only IMHO. I shot 50 sheets.

If you have been experiencing problems with the tonal range in certain situations don't you think the speed rating may be slightly optimistic?
In bright sunlight do you think that a half stop pull would be beneficial?

For what it is worth I seem to have had the same experience & I was wondering if I was exposing and developing it properly. I have shot with both coated & uncoated lenses, but not yet a comparison with the same developer used with some FP4.

The next sunny day we get I will shot some ERA and the Foma side by side.
I am interested in the Shanghai 4x5. From my initial experience of the ERA I think it is best left for studio use 'cos the chances of me getting a sunny day with deep shadows don't seem very good.

After experencing the shadow dropout at the end of the box I did not purchase and test another. I think that metering so that the deepest shadow you want detail in is 1 stop below the exposure setting then pull the developing to prevent the highlights from blowing out will work or just use another film on those higher concrast scenes.

The Chinese ERA seems to have lower contrast.
Have you gone back to using Ilford or Kodak, because you said that you haven't bought any more Foma?
I wondered itf the Foma was un-naturally rated by its behaviour.
Did you encounter unusually poor detail at the bottom of the tonal range when you were using the Foma on a day when there wasn't such a long tonal range?

Has anyone got their $0.02 worth to add on the subject of the Shanghai?
Some of the stuff i've read suggests a soft emulsion prone to damage and maybe curliness of the base. We are talking about the blue box 4x5 sheet, not the Shanghai GP3 roll-film that looks like a knock off of the Ilford FP4 packaging from some years back.
I'll give the Shanghai a go when I have munched my way through the ERA.
I would like some pointers to get the best results.

I am currently working my way thru a box of TriX 320. Next will be Tmax 100 and 400. Delta and HP5+ remain at the top of my list.

I have some Kodak 4125 copy film that I use that for important landscapes. It is rated at 12 ASA for pictorial use, but I trust it.
How far do you trust the Foma, Shanghai or ERA?
Another thing: How good is the detail rendering of the ERA compared to the other two films? I was trying a old brass W.A.R at the weekend and the results weren't too sharp. It could have just been a poor lens but I won't know for sure till I have tried shooting the ERA with my other glassware.
I decided to buy some of the Shanghai out of curiosity, we'll see how it performs.
Does the maker of the Shanghai have a Web site?