Our house was a shared ownership. We purchased 60% of it and eventually staircased to full ownership.
For us, it enabled us to get on the housing ladder far quicker and buy a house in a desirable area which we wouldn't have been able to afford without the scheme.
The rent was pretty cheap for the remaining 40% and the monthly fees were only about £20 a month which included buildings insurance. When the rent did go up, it was usually only a few pounds a month.
Now we own the house fully, we own the freehold and we do not pay any monthly fees. The equity in our house is around £40k, so we will either use that as a deposit if we decide to move, or towards an extension.
I would recommend shared ownership, it worked really well for us. The people who it doesn't work for usually aren't intending to stay in the property long term or aren't aware of the costs involved.
The only annoying issue I found with it, is when staircasing you obviously have to go through all the paperwork again, so instructing a solicitor, paying mortgage fees, you have to pay for all the searches, pay for the housing associations costs as well - so it adds up. It's better if you intend to staircase to do it in one go, rather than multiple.
Also once you own any % of a shared ownership property, you are no longer classed as a first time buyer - so when you staircase (assuming the initial cost is below the threshold), you have to pay stamp duty - even if the total house value is below the stamp duty threshold