I use a domain from GoDaddy for my business' website and email.
I use IMAP settings to read email with MS Outlook on my PC and default reader on my Android phone.
I went ahead and got Google Doc paid service for the $50/year, and ported my email to Google (keeping my domain name).
I use the calendar to schedule meetings and they show up on my 2 PCs (Outlook) and my Android phone.
I do NOT use the documents part of Google Docs; instead I use Dropbox and I like Dropbox better.
 
Now that my 1 year is expiring, I'm trying to figure if I need to keep the paid Google account.

What exactly do I pay the 50 bucks for?
I can't find a telephone number to call google and ask them what benefits the $50 gives me, but I'm sure there was a reason I did it a year ago. I seem to recall it had something to do with Outlook not being able to sync with my phone using the free account.
GoDaddy people tell me that they have calendar option and that it works well, but I haven't used it yet.

You can do all of that for free. The hardest part for me was getting my iPhone to use my work domain for outgoing emails rather then my gmail.

I want to drop GoDaddy myself. Their calendar is fine but the Google calendar is just so easy and sync's with little to no effort. For a while I was having a weird problem with GoDaddy and their email client. I would log in from the computer and it would do something weird when I composed new emails. I could write an email but it would give me an error when I went to send it. I cleared the cookie for the GoDaddy email site and that seems to have fixed it.

I just spent few hours looking over and calling Google and GoDaddy people.
End result -- I'm keeping paid account.

From what I gathered, the only real differences between the free and paid accounts are:
Free             Paid                 Notes:
7Gb Mail       25Gb Mail         I'm using 3% of my 25Gb, so that would not matter
Single Cal     Group Calendar   I'm 1 man shop so I don't care either way
No Outlook   MS Outlook sync; That's a big one for me and a reason I'm keeping paid service

I use my Outlook for mail, contacts and calendar, and without paid Google account I would have to use GoDaddy's service, which is $107 a year. So yes, I'm going to keep my $50 Google account.

Well, I'm cheaper than that, and balked at having to spend $20 or $29 for an Android app that made it possible to sync Outlook with my Droid 2 Global.

I'll let you know what that is/was when I get back to that project.

Wow, you wouldn't pay a small one-time fee that would have made it possible to sync with Outlook, which you like and use? You are tight!

I'll tell you a joke (half kidding) about the CEO where I used to work. The story goes:

I was talking with a friend who left the company, as he got hired away by a competitor. He commented, "Remember when you started, Jack gave you a penny, and told you to clench it between your Ass Cheeks, so that you would remember that saving money is always important?" "Yes" I replied. He responded, "At my exit interview, Jack walked into the room, and wanted his penny back!"

Sounds like you give the CEO at my previous employer a run for the money!

:-)