No, with 1,831 Contacts I don't have a convenient way to find the missing/duplicate 3.
I followed the usual troubleshooting maneuver of logging out from a machine, removing all iCloud data, etc. I did that on my Air and my iPhone. None of the counts changed.
Incidentally, the MobileMe to iCloud transition on my Air failed and left the machine in a curious MobileMe/iCloud state (the Pref Pane crashed and sent an error message to Apple). I think I've fixed that though; i had to remove accounts in Mail, Contacts and Calendar prefs. Despite cleaning out the MacBook, when I was done it again has 1828 Contacts.
... 1831 contacts on the iCloud site, 1828 on my MacBook Air and MacBook, and 1829 on my iPhone. The "reference" address book prior to migration had 1831 contacts.
My first inkling would be that one or more of your contacts either doesn't meet the rules for iCloud, or has text or photo that is causing a problem. Obviously without being able to isolate which contacts are causing the problem, you would not be able to examine the contacts for these possible causes.
Yes, my contacts are old. They probably go back to Classic. At one time they were synchronized by Spanning Sync. I would also wonder about an illegal character.
Or perhaps there's a duplication problem with iCloud.
I own Contacts Cleaner. I'm going to run it against my old Snow Leopard Contacts collection and look for issues, then correct those issues on iCloud.com and see if the fixes propagate.
Synchronization has been the bane of my existence since I first used a Palm device...
I've figured out a part of the problem.
Each time iCloud synchronizes with a machine it's been duplcating the contents of the Notes field on my contacts. I checked my Snow Leopard original and it didn't show this problem, it wasn't a problem in MobileMe either.
I'm so glad I didn't move my main machine and core Address Book to Lion / iCloud.
This is now an official "synchronization train wreck". I'll be bailing from iCloud, and will probably drop (way) back to synchronizing my iPhone via iTunes.
Mercifully, save for lack of sleep, minimal damange was done.
I think I've figured out the bug.
It's the oldest bug in the book -- line termination. (http://en.wikipedia.org/wiki/Newline)
My Address Book contains contacts that started out in Outlook, then went via MobileMe Windows Control Panel to live in MobileMe, and then into my desktop machine.
MobileMe could handle the CR vs CR/LF difference. So can Address Book in Lion and in Snow Leopard.
I'm seeing extra line spaces in all of my contacts with notes that started out life on Windows.
Each time iCloud does its sync with desktop it finds a mismatch -- because OS X and iCloud handle CR and CR/LF differently.
So it replicates the Note.
The Note grows eternally, until everything crumps.
Nasty bug! I hope Apple figures this one out soon.
I'm updating my blog post  as I work this bug.
I found an OS X Service item that will convert text to Macintosh line endings. So I can fix my Notes one at a time using this.
I can also use Bento (demo download) to identify which of my Contacts have Notes. Since I know which came from Windows originally, it may be most practical to use the OS X service to fix the Notes field one at a time.
I've found I can test for iCloud.com incompotabile Card Notes by vCard export. Contacts with Windows CRLF in Notes have duplicated /n strings in the vCard. After the Service fix they don't.
So It's tedious, but probably practical, to manually fix my Contacts this way. I thought of trying to use Automator or AppleScript to do this, but it may be faster to do this manually.