As Whiff stated, I moved from a house to my flat. Just a normal flat in a bloc, was very put off with Retirement flats due to their size, (particularly tiny kitchens), and maintenance costs. I have a 2-bed flat, large double aspect Living/Dining room, en-suite and guest bathroom, plus garage. Had EPC both for the house I sold and for this flat.
As Secretary of our volunteer Management Company, I deal with Solicitors when any of the 25 flats are being sold, I do find that so much of this is handed over to clerks in solicitors offices. I have no legal training, it has been a large learning curve for me - but find I am often now in the position of advising conveyancing solicitors (their clerks) on the appropriate forms and paperwork required. So much of the delays in this is caused due to the people landed with the job do not know what they are doing.
Do use a local company, one where paperwork can be handed in - not put in post, etc. Know the name of the person, nominally in charge of your conveyancing. Find out somethings about the Maintenance Company for the flat you are thinking of purchasing. Our maintenance charges include annual service of boilers AND a 24/7 contract with British Gas for repairs etc to Central Heating, etc. as well as including all water charges.
As a volunteer maintenance company we have a vested interest in keeping all costs as low as possible, and nothing is paid out in salaries or to shareholders.
Do beware that many of the Retirement flats have controls in their leases as to what alterations you can do in your flat, and even who you can use to carry out any work. Also, some can only be sold via the Company who take a percentage of each sale.
I know you stated you take what is best for you at the time. However, in any normal (not specifically retirement) flat it would quite simple to set up a help package - you do not actually need a house manage on site for this. And, they are usually only there 9 -5 Mondays - Fridays. A call alarm system can be put into any house or flat, at quite a small cost. Personally, I do not even bother with that, but would use Alexa should I require an ambulance or other assistance.
In any flat you will not require any building insurance (that is always part of any Maintenance charge, so only contents insurance.
If you wish to ask me anythings specific, please PM me.