A group claims to have achieved S-OFF on the One (http://androidspin.com/2013/05/01/htc-one-s-off-achieved-htc-users-can-now-rejoice-as-well/) but they are charging for the service and you are required to send in your phone, which may indicate that it is a JTAG method.
What we need is a software method. I'm fairly confident this will happen, but I'm basing that on nothing by my perception of HTC with the release of this phone and their activity in the community (including their presence on Reddit and other forums where they are actively collecting user feedback).
In your dialer type
*#*#4636#*#*
Should bring up all the info and you can see if it's like band 4/ etc
let me know if this works.
Okay I'm assuming your on dev edition RUU now?
Did you notice any difference in speeds or nothing so far?
Let me do some research and I'll post back, did you goto an area with edge and see if it did anything?