The GUARANTEED 4pm check out for FHR can be what swings me from Virtuoso.
I have, for eg, used Virtuoso in the past for Four Seasons Hampshire. On our last stay, though, our usual 342 rate was not available and the standard prices a bit scary. By booking for just 2 nights but knowing we would be guaranteed a 4pm check-out, we did much the same stuff as if we had stayed 3 nights.
('cos after 4pm on a 3 night stay, all we are doing is getting a snack with the kids, bath, early bed, wake up, breakfast, check-out!)