Thats pretty much the only major differences to be honest.
With the Vario II you can browse the Internet at HSDPA speeds (providing you're in a good 3G area), connect to your home wireless network (phone has Wi-Fi connectivity), install Tom Tom sat navigation softwaree and all sorts of other Pocket PC software that enhances the usability of the phone. Some great emulators around so you can play loads of games.
As a phone, it manages ok. Reception is crystal clear, something I was extremely impressed with seeing as it is virtually a PDA with phone features slapped on. Dialing numbers is fine for me. Once you've set up the speed dial list, you simply use the scroll wheel to select the number and dial. This function is pretty much the same as scrolling through the phoneook but with the numbers you want. (I always have numbers that I'm dialing all the time and the other 75% that are just there). Entering a number by hand would require you to either:
1. Whip out the stylus and tap the numbers on the phone pad
2. Use your fingers to tap
3. Slide out the keypad and use that
Texting with the keypad is a joy to use in my opinion. Don't have to to battle with the predicted text as you sometimes do and its quick with two hands. Think you'll stuggle texting with one hand though if walking down the street but making/recieving calls isn't a problem.
For 2MP's, the camera on the Vario II isn't the greatest. But having the image sharpness set to 5 by default doesn't help. You won't be winning photography competitions with it but for the odd snap or 2 it'll suffice.
My girlfriend has the 6233 and its a superb phone. If I wasn't bothered about PDA functionality its something I'd go for.
Build quality is superb and just looking at it you'd know it would survive a major drop or 2. Don't think the Vario II would somehow
The keypad is fantastic and menu speed is great. as a phone, it handles calls and texts brillianty. The display is great and battery life superb. My girlfriend is always impressed at how many days use she gets out of a charge.
Vario II on the other hands isn't as stellar. With light useage (few texts a day, few calls) I can go 3-4 days without charging. Problem is with a phone like this, you're noting going to use it just for calls! At worst, you'll need to charge it everynight/second night depending on how you use it.
Hope this helps.
By the way, any more comparisions you want between the phones just ask.