Originally Posted by
YuropFlyer
The business lounges (there are just two of them, the main one, and the D Non-Schengen one) are about the same. Never showered in the D Non-Schengen, but showers are available in both. If you're departing from D, use the lounge there, otherwise (departure E gates), then go to the main Business lounge, use the shower there.
As the showers, at least in the main lounges, are located within the Business part of the lounge, there is not (much) need to go to the Senator part.
I have no experience of using a shower in the Business/Senator lounges in ZRH but the shower for the non-Schengen lounges in D is down the corridor (as are the toilets) and not in the lounge. From a report in this forum it sounds ok.
However, if the OP is coming from outside the airport and departing from E, the Schengen Business Lounge would be more convenient. You only need to go through security once and passport control once. In order to go to the non-Schengen lounge on the way to E, the OP will have to go through security and passport control before the lounge and security again after arriving on Heidi's train (or passport control twice - into Schengen and out of Schengen).