Four things you must consider if you want to make a good impression on an editor (and one thing that is just good to do anyway):
1. Don't just study submission guidelines, follow them. An editor is within his or her rights to reject a manuscript solely on the formatting being a mess. The story may be very good, but how are we to know if we cannot read it? Allow your genius to shine by formatting properly. Yes, I know, I dislike Courier New too. Yet Courier is one of the easiest fonts to read. Word count and page count estimates can be simplified, and therefore how long the project will take to edit. If all manuscripts we receive start out the same, comparing one to another becomes much easier.
2. Name-dropping (comparing your work to other authors) in the query is unneccesary. Chances are I haven't read those other authors.
3. Telling me in your query how (adjective) your story is will not impress me. Allow me to be the judge of what adjective to apply. Every reader and reviewer will have their own opinion. Telling your reader what to think can spawn a negative reaction.
4. Make sure the synopsis shows the entire story; beginning, middle and end. A good synopsis shows the emotional turning points as well as the main plot, and gives us the names of the major players. Outside of that, don't stress too much about it. We know that synopses are difficult to write. The partial manuscript is our sample of your writing, and what we give most weight to when deciding if we want to see more.
And, good advice in general, 5. Back up your work regularly. Keep drafts separate with new file names--you never know when you might want to rescue a scene you cut at one point to refurbish somewhere else. Back up on different media and keep the copies in various places. At least one copy should be kept outside your residence, just in case. For example, I use CD's, USB key drives and an external hard drive.
When comparing apples and oranges, and you're only looking for apples, the choice becomes obvious.
Don't be an orange.