My ds has dyslexia, and did fine in independent mainstream.
But you know your own child best, and will be able to make a good decision. Nothing is perfect, though, so don't cane yourself when things don't go quite right.
The really useful bit of advice we had was to be prepared for the dramatic increase in the amount of writing in secondary. Even then, we were taken aback. It is much harder to sort an essay when your brain is distracting you with problems of spelling etc.
Talking to staff in mainstreams, as we went round on open days, it was very clear when there was no proper SEN system that could distinguish my ds, who tried hard but was up against it through no fault of his own, from the rebel kids who were capable but lazy.
So those schools went out of the picture.
The special schools were spending more time on dyslexia stuff than he needed. - a laptop and not being told off for things he couldn't help were enough -
As a result of mainstream, he had to endure a bit of teasing for mis-spelling eg his own name, but he had the type of personality that could brush that aside (being an excellent sportsman helped).
He will now tell people he has dyslexia (and dyspraxia) if he needs to, but is far more likely to talk about the things he can do - which is, of course, what we all do...