Considering I started this thread I'd like to jump in a bit and offer
my take on this.

I normally like independent travel for several reasons. I am a
semi-professional photographer and I dislike package tours. I like the
freedom of exploring an area on my own timetable and setting my own
itinerary. For the most part this works fine for a US national park
strategy or for independent city touring. There are numerous lodging
choices for every accommodation and in most cases it's quite easy to
pick up and leave should your choice prove poor. Should one choose to
camp, the logistics are easy to put together. Depending upon where you
are the most dangerous thing to contend with from a wildlife
perspective is bears. There is a wealth of material available from
public and private sources on the national parks. Renting a car is
simple, roads are well paved and marked and are not dangerous. In some
ways I understand Eben's approach because I too have a hard time
understanding why people take packaged tours to national parks in the
U.S. it is so easy to do by yourself.
On the other hand I am finding Africa much harder to deal with as an
independent traveler in reference to safaris. Here is why:

1. Airfares from the US are prohibitively expensive. Yes there are
consolidators that one can use but most people do not go or understand
that route. Package tours do offer great airfares. There is a company
called UTG (US based) that has airfare with their packages for $1000 no
matter what the date. That is almost impossible for the average person
to get without a tremendous amount of running around.
2. Self driving is really not an option in Kenya. The majority of
Americans, myself included, do not drive standard shift. Furthermore I
think that a 5 hour drive from Nairobi to the Mara that requires a 4WD
vehicle is beyond the driving skills of 90% of the population. Sure we
own Jeep Cherokees, most are never taken off road. I'd be reluctant to
do so without more experience. It's not like I can call someone to get
a tow.
3. Independent camping is not an option. Pretty self-explanatory.
4. Lodging is limited. The available choices are expensive and you may
not necessarily get a better deal once you add in extras like game
drives, etc... Not all lodges provide this in the price. The Serena
properties are a perfect example.
5. Finding a guide company is problematic. Go on KATO's web site and
you will find many companies that offer safari. Most follow the same
itineraries. I've e-mailed several of them asking about customer
itineraries. I've received a response from one. Several of the
e-mails bounced back from the addresses that were provided on their Web
Sites. I can tell you that doesn't inspire much confidence. It's in
these situations where relying on a tour operator to take care of
logistics is comforting.

I have appreciated both Eben's and Liz's input to my original inquiry.
I've found Liz's sight very helpful in learning more about the areas
that I'd like to travel in. Travel is a very personal thing for
different people. Everyone's goals are different. While frustrating
for you Eben, I suspect that the tourist in that mini-bus is just as
thrilled as you are to be there and may not be interested in mingling
with the locals. For that matter the locals may not be interested in
mingling with you. I'm also spending a lot of time doing research.
Personally I enjoy it, but the average vacationer likes to be presented
with a package deal. I've also read many of Liz's post and while she
does mention several companies most are in direct response to someone
asking (and to be fair Eben, you did ask Liz as did I) and she doesn't
push or promote it. I would have no problem mentioning a company I
have done business and that I was happy with their service.

I also think the minibus issue is being beaten to death. One of the
primary reasons that I'm looking into a private safari is that I'm
concerned that I will be part of a tour that will come up to a group of
lions, take a snapshot and then want to leave. I personally believe
that to have a quality experience takes patience and observation. If I
found a group of 4 individuals who were like minded I'd have no
hesitation joining a tour group. As long as I had a window and a
photographic hatch I'm happy. Hint Hint... If you were planning to go
next year drop me a line and we can all book a private safari together.

For myself I'm working with someone now on a quote for a private
safari. Hopefully it will fit into my budget. If not, I have no
problem joining a tour and treating it as a scouting trip for a later
date. To each his own.