From the perspective of someone just starting out being
dual homed, this will be very different. You are not going
to get 7 transits and you are not going to be able to peer
85% of the traffic. That is why I advocate that it is better
to buy transit from a middle tier company. Instead of
getting a connection to just one so called global carrier,
you get a package deal with connection to all of them and
85% peering one step removed. Plus many of the companies
that the middle tier has a peering with, is something the
tier 1 companies would refuse to peer (exception Hurricane
Electric).
Also while your company may not need dual connections to
each transit, the situation is completely different from the
perspective of a small dual homed customer of yours. That is
a lot of paths that are lost if this customer where to
experience a disruption to the connection to your network.
This is especially true if there is an unbalance between
the two chosen transit providers. Say the other provider is
Cogent, which are famous for refusing to peer. That means
that all those peers, unless they have a Cogent contract,
they will need to find an indirect path to replace your
peering.
Of course I may also recommend to simply set your
expectations modestly. Dual homing will get you redundancy
but unless you line up all your ducks correctly, you should
expect some brownouts in the case of a link failure. Simply
tell the boss, that unless he wants to pay at least double
in every way, there will be expected downtime in the order
of 5 minuttes in the case of a link failure.