If I went again I would go for an evening session - As I suspect that that the short summer evening sessions are not so busy with semi-pro drivers. When I went about 6 years ago on a Saturday there were all sorts of Very fast sports cars on slick tyres with drivers in full fireproofs passing me like I was standing still. When you are doing about 110 and three Porsches come past you about three feet apart doing in excess of 150 it's a bit intimidatiing. Needless to say my lap time time was pedestrian. A member of our bike club has raced cars there for several years and has done in excess of 1000 laps and he reckons it takes about 200 to learn it enough to go fasrt.
There would appear to be a surfeit of prolixity and sesquipedalian content today please do not use a big word when a singularly un-loquacious and diminutive linguistic expression will satisfactorily accomplish the contemporary necessity
I took our Caterham 7 over there for a weekend in 1998 - it was an event organised by the Lotus 7 Club of GB (and run by an independant company who specialise in this stuff) so there was exclusive use of the track for both sat & sun.
Saturday consisted mostly of tuition, sun morning was re-cap and sun afternoon was a free-for-all. We were told to look out for corners where lots of specators sit - the more spectators, the more dangerous the corner.
Utterly terrifying, and thrilling in equal measure. Not sure I'd want to do it on a bike though.
If you have not been before, steer clear of weekends.
Either do an evening session or get there first thing well before the barrier goes up and be at the front of the queue. That way there will be less traffic, but much will still come flying past you in unlikely places. The big problem is other folk seeing red mist and then getting it wrong. Also drivers with fast cars and no idea, as well as people in everyday cars (and fast ones) who know it like the back of their hand. Same applies to the bikes.
Ride mega defensively and only to 80% of your own ability, use the mirrors as much as looking forward and you should be safe. Do not do more than 2 consecutive laps without stopping for a breather and water / coffee etc.
Check with your ins. co. also as most now exclude the 'ring.
I also know 2 ring instructors who say it is now too dangerous on public days, so they only do the rare closed sessions.
Pays yer money and takes your choice. Good luck.