For what it is worth, I have started mixing and matching. LS400 needed new pads and discs on front - had that done by local engineer at £100 less than Leus Hatfield estimate. Needed front caster arms replaced - had that done at Lexus.
For 63000 mile service called several main dealers and using LOC discount got the work done at Lexus Bracknell for £160 less than Hatfield (including LOC discount). Other main dealers were more expensive than Bracknell.
£90 per hour is a leg over rate - so keep on checking around and passng on the good news on who has reasonable costs.
By the way, if I was running a Jag I could find an independant service outlet reasonably easily. Anyone know of any independant Lexus service shops?