The problem with roundup ready bent is if it is grown in a shady, compacted, poorly drained area it will be thin, like any bentgrass. Anybody who thinks they are going to have pure bent stand in areas without sun, the proper drainage, and heavy traffic are wrong. Instead of a bent/poa mix, they will have a bent/dirt mix. Where there is sun etc, new agressive bents will fill in and be dense and out-compete poa.
Roundup ready is a marketing ploy trying to simplify a complicated problem. We have chemicals against poa already, we just don't use them because of the devastation they would cause in a green that was just 25% poa nevermind 75%.
Give a trained superintendent a chainsaw, Prograss, bensulide, and allow him to regrass with G-2 and the results will be much better.
I have also heard that the roundup ready bent is a ugly grass just a tad better than penncross.