NATS to provide at Lulsgate

[flower]

Because the airspace that you are transiting through is delegated to Cardiff not Bristol.
The procedures off RWY27 mean you get climbed to FL60 we then do the climb up to the next standing agreed level, procedures off RWY09 allow for you to be climbed up to the next standing agreed level however you are in confliction with multitudes of traffic coming from multiple directions.
You are also only hearing one frequency they are other frequencies operating against which you may have conflicting traffic.Cardiff is integrating traffic from a number of airfields not just Bristol into a stream of traffic spaced for the next sector, A considerable number of Military crossers transit that airspace, we have Filton traffic which is operating on Filtons frequency which we give cleared flight paths too.
What may seem a quiet sector is far from it.
The system works and particularly off RWY 27 works exceptionally well.
Can you imagine yourself asking the same question on one of the London TMA frequencies, stop thinking of it as Cardiff and start thinking of it as the next enroute frequency then it should make more sense to you.

( had to have a bit of a giggle when I discovered that some call us the Cardiff TRACON, all in fun of course but not that far from the truth)

Gonzo,
what you have written is how it used to work and yes it was a nightmare at times, tying down the procedures to the ones we have has increased the flow of traffic through the sector and made it a lot safer.
When the additional delegated function was done it was not produced in isolation, neither were the procedures to which we now adhere.
Bristol ATC management were fully involved at all stages. As a unit we work very closely with them, I personally would be delighted to see them Join NATS.