Carl Dickson

This one has a much better introduction than the others. If you compare them side by side and pretend to be the customer, which would you pick?

That said, it could be improved a lot. They talk about generalized facts and requirements instead of inserting themselves and saying what they will do to achieve results. This is actually a good example of why it's better to demonstrate understanding through results than by talking around it like they do here. But at least they are talking about things that matter.

This is a good example of how good looking a really simple layout can be.

But the cover letter/proposal introduction is typically bad. The best I can say about it is that it's short.

In the "Project Understanding and Approach" section they used passive voice. That makes this sample a good example of how not to write proposal text. Imagine how much more effective it would be if instead of saying things like "Collection of base and background information will be collected at this time as well" they said things like "We'll collect base and background information at this time so that we can approach this project in the right context." By getting rid of the passive voice, they become involved (instead of the performer being unsaid) and by adding a benefit so that the action has a meaningful result.

This one has a typically bad opening. "We are pleased to submit..." followed by platitudes, followed by a lot of them talking about themselves and how great they are. They somehow manage to never say in the cover letter what they'll actually do for the customer. They never link their experience to the results that the customer can expect.