Yes I know it's a good problem to have.
I line an easy life so even though I though in RE at first, it seems like too much hassle and not enough ROI.
Investments (via a broker/advisor) I don't know, but for some reason I don't fully trust it. I'd be happy to do it with a bank though.
The last option (and most sensible one) seems to be to pay off the mortgage, and get an ISA where we put our savings.
BTW pensions wise, we seem to be doing OK (even if I think it's quite small these days, projections show it will be ok once we retire, and I'm pretty sure we don't need 2/3 of our income).