The first experience described earlier:
http://www.flyertalk.com/forum/14318335-post1.html
The last opt-out was yesterday at OMA. They ran the WTMD and WBI side by side with one entry line between the units. There was a TSO barker that was telling the crowd that he'd worked there for 8 years so they'd better listen to him. He was complaining that there was no room on the xray belt behind the scanner because there were too many bins piling up. He said people needed to make sure shoes, gloves, hats, belts, wallets, papers and watches were placed directly on the belt to save space. This seemed pretty ridiculous; I'm sure he meant to use a small tray for some of that stuff instead but was in no mood to be questioned.
As a side note: BOS had the same problem when I went through -- bags/bins/gear were piled up on the belt after the scanner. People there were separated from their belongings for several minutes there as they waited for WBI or went through patdown afterward. The belt only moved forward after someone finished WBI and gathered their stuff.
Anyway: Just past the TDC was a TSO sorter that told me to step towards the box (seemingly random selection). I did as she asked; the WBI operator then told me to get in. I told the WBI operator I was going to opt-out; she told me to go back to the sorter. That really seemed to foul things up because when I return to the sorter I was blocking the single entry line. The sorter was frustrated and asked me to push myself up against the side of the WBI machine so that others might be able to slip by and go to the WTMD. She called for a male assist -- that action apparently stopped WBI operations for whatever reason. The next person in line for WBI was turned around and sent to do a normal WTMD screening. (I'm glad that at least one other person was able to benefit from my opt-out).
After a brief wait a TSO came up and had me proceed through the WTMD and then go off to another area to stand on the footprints. He seemed angry but didn't say anything other than "arms up". He did not explain anything further like using the back of his hand for sensitive areas, offering a private screening area or anything like that. He was the only TSO nearby.
He used both of his hands together and pressed *very hard* as he dragged them down my legs -- enough to pull my pants down a bit. After 30 seconds on the legs and feet, he grabbed the frank and beans without warning and did a short squeeze. It was hard enough to make me jump an inch into the air. The surprise grab wasn't painful -- just unexpected. There was more hard rubbing on the back and chest, then he finished off by telling me to sit down and show him the bottom of my feet. He kind of scratched at them a bit and told me to wait while he tested his gloves in a machine. He didn't return, but waved me off from the machine area after the test instead.
The nature of this patdown was a bit more rough, aggressive and less informative than prior ones, but as we all know, TSA procedures and professionalism varies from location to location. The short of it is: If you decline WBI, you're going to get groped. If you go through it, you might end up getting groped anyway.