Main issues with Hosted SIMS are the limitations. For example, you can't access VBA/Developer if you intend to write code into your reports, etc. You have to purchase a separate code signing license if you want to access this. Even then, you can only sign the code, still not access VBA editor, etc. You have to do all the work in a local Excel, then move it over to Hosted for use in the Hosted Excel.
Even more basic things, like opening a SIMS report in a browser window - they don't even allow the right-click to export to Excel!
I've used local SIMS in many environments and Hosted is just that tiny bit slower moving between screens. Only a fraction, just enough to be noticeable. This is even when accessing it from home with a super fast fibre connection - so no delay with school internet.
Also, Capita determine when the maintenance periods/patches and filesets are uploaded are - and often don't contact before it - I've had to resort to putting a Watch on the Capita Service Status page for updates.
I can also count at least 5-10 times in the last few months when there's been issues and you can't login/it crashes. Sometimes only for 5-10 minutes, sometimes for an hour or two.
So many of my calls to my local SIMS support start with 'Oh, you're on Hosted aren't you?'