getting a really anoying rattle from the engine in forth and fith at around 2000 revs sounds a bit like it's strugling but not if you know what i mean. and it only does it if im accelerating.
anyone else experienced this?

yep. A common problem that's been mentioned on hear already. i get that sometimes. My solution is never to put the car in those gears at such low revs. It's a horrible sound!

That noise is engine knock and doesn't really do the engine much good, try using the gear lever!!!!!

Well there's a problem I don't have for a change.
I am quite impressed with the way I can leave the in top gear and pootle round town as low as 25mph and it will pull away no problem. This was the way I was driving the Demo car too. I wanted something for Performance when you want but was also practical on those lazy days in traffic.
I regularly change from 2 nd to 5th at 30 in 30 mph limits
Its not quite as much torque as the 2.9 4x4 Sierra I used to own but its not far off. That would go down to 18mph in top then pull away and leave most cars that were in lower gears

well i used to be able to do that in the golf then the clutch went!!!!