Having worked in 6 different countries, I can reliably inform you that the standards in all 6 are equally as good. Where the differences occur is in the execution of the control. A crew of controllers from diverse ATC backgrounds is, in my humble opinion, far superior to one comprised solely of home grown "talent".
Different countries have developed different strengths, be it tactical flow control, use of ADS-B, pilot education programmes, remote approach control etc all bring something unique to controlling.
Maybe, NSL losing a few contracts will allow new companies with fresh ideas to be allowed to show how ATC can be improved in the UK.
I have worked in the UK and know that NATS/NSL can be very reluctant to embrace new technology/procedures. Let's hope the contracts are awarded to some of the innovators.