Thanks for this; I'm in the early stages of looking in Cambridge, have never lived in the UK before whatsoever, and had no idea (yet) of the low quality of the listings on rightmove, etc..

[Side note: current coverage is London, Manchester, Liverpool, Birmingham, Nottingham, Bristol, Newcastle, Leeds, Edinburgh and Glasgow... any idea when Cambridge might be added to the mix?]

One thing I've noticed in scanning different sites is that the data at the source is often quite limited, possibly intentionally. The different sites have the same limited info; and I'm fairly sure the reason you don't have searches based on "children allowed" or "pets allowed" is because this isn't recorded reliably (or in any way consistently)... it's just occasionally in the text description, worded however (possibly with spelling errors).

As long as you're aggregating the same limited data, there's only so far you can go.

Input from searchers could be the way out -- like the idea of letting users flag scam properties, or add other info after talking with the agent -- but this may get hard to protect from abuse, frustratingly.

If you can fix this problem, you've got a goldmine in your hands. Never mind the map, simply knowing that the flats you're looking at are actually real would completely change the experience (the map is very handy though - keep it of course).

I think you nailed it. Definitely the way to go.