AEK and SLM banks (small bank in canton Bern) - any one having any feedback?

Good afternoon,
anyone having any experience /feedback with AEK and/or SLM?
They are both small banks in canton Bern and I am truly interested to see if they can be used in practical and efficient manner (yet safe) to diversify in these days of massive polarisation.

Any other suggestion in canton Bern ?

Thanks a lot in advance