In the Indie they start formal testing in Y3, with termly assessment tests sat in the classrooms with the desks moved. By Y5 they are still getting termly assessment tests but they also have formal exams in the main school hall, in rows, at exam desks. Y6 have 2 sets of formal exams in the hall with another set in the autumn term as a practice for the CE in January.
My dd is in the state system in Y5 and she does not get tested at the same level and all tests are in a much more relaxed way within the classroom. She will be doing her optional SATs in a few weeks but there is no weeks of revision, which has been happening at the Indie, and the kids will not get stressed out by them.
I know which system I prefer, but I can also see how the Indie way prepares the kids better for GS entry as they are not put off by exam situations and timings.
It's funny, we've found the opposite. Perhaps DS is lucky at his school; they are very relaxed about testing (they don't do SATS). His friends in the state system however get really stressed during their SATS with piles of preparation. One of the friends of my daughter refused to go into school as she couldn't face it. She was made to and started crying and they had to go and pick her up. Shows that all schools are different, no matter which system they are in.