I also needed to get 20 points for Superior English. I'm a native English speaker, originally from the UK. I work in a role that requires extensive communications, so it's not unusual to write multiple articles or documents a week. I thought I'd sail through.
My initial instinct was to go with IELTS, but availability was pretty poor for quite a long time, so I had a look at other options. PTE-A is not available in my location and most the other tests seemed a bit exotic in their admin. So that left TOEFL. For Superior you need to score L: 28 R: 29 W: 30 S:26 out of 30. That means writing needs to be "perfect".
The test was in a packed location. It was noisy, the keyboards were old and required hammering on the spacebar. The test itself was straightforward and, frankly, presented few problems. I'd already checked on form and format prior to taking the exam and there were no surprises.
Two weeks later my results came in. L: 30 R: 30 W: 27 S:30... I asked for a remark, with no change. I had been VERY confident on the writing section, having written numerous pieces of a similar style on a regular basis. But still, I returned to the books, studied further. I'd covered everything, even adding some extras to make the pieces shine: variable pacing to maintain interest, avoiding passive voicing, adding a little alliteration to be playful.
I booked another test, sure that it was perhaps a spelling error or two, or perhaps bad luck. The experience was even worse, with incredible noise levels, heat and a PC that had problems. The test results came back two weeks later: L: 30 R: 30 W: 27 S:30. I couldn't believe it! I was f'ing LIVID. Again I handed over cash for a remark and, yes, again it came back with no change.
Getting desperate I tried to find a way to take PTE-A. In the end I booked it in another country, and paid for return flights and a hotel. The exam experience couldn't have been more different. The environment was professional, the exam room dimmed with modern equipment and only a handful of candidates. The test itself was tough. It was far more challenging than the TOEFL. I walked out with some doubt. I felt like I'd been stretched, and required to prove something. When I thought back on TOEFL, it felt more like a game of "Simon" where one fault would sink your chances. But still, my performance didn't feel flawless. My results came through the next day L: 90 R: 90 W: 90 S: 90.
I'm still (9 months later) very angry about the whole TOEFL experience. There are charts available that line-up the scoring ranges of the different tests to allow comparison. The top end of PTE-A is head and shoulders above TOEFL. I have a strong impression that TOEFL failed to correctly assess my English capabilities. I would advise others not to take this exam if you require Superior points.
