I've had a chance to use all 3 shampoos now.I thought I'd give a short review of each and list them in order of preference.
I do a a two bucket wash with 4 gallons of water in each bucket, adding the amount of soap called for on each label ( 1 oz / 2 gallons water ) and using a wool mitt.
My main shampoo to date has been NXT or GC if NXT isn't available. I used WG and 4* on the TSX which has UPP x 2 and PB was used on the Integra which has WG x 3. None of the shampoos seemed to remove any of the slickness of the sealants any appreciable amount.
WG: The slickest of the three. The mitt glides very easily across the surface and leaves a clean surface with a nice gloss after drying. Lubricity is better than NXT and it produced lots of suds that stayed for the whole wash. It has the "WG signature scent" - something like an inexpensive cologne that I actually liked.
4*: Lubricity is about the same as NXT. It cleaned easily and also left the surface with some gloss. Suds lasted for the whole wash and it has the same coconut/banana scent as UPP and UGE.
PB SS&S: I was a bit let down with this one. I had expected it to be at the top of my list after the reviews I've read. Lubricity, which is the main thing I'm looking for, was on the same level as GC and a little below NXT. Suds also stayed for the whole wash and like the others it easily removed the dirt from the cars and has a pleasant peach scent.
That being said, they're all good washes and I'll use the remainder of them without hesitation. Will I order any of the three again? WG is the only one I would consider. I just didn't find the other two superior to NXT.
I'm sure differences in water affect how shampoos perform so what works best for me might not work as well for someone else. I hope this helps.