Verizon MiFi vs. Sprint's Overdrive

Both me and my fiancee are planning on purchasing an iPad. We hope to be able to go with the standard WiFi iPad instead of the 3G version because of the extra $130 and also the extra cost for the data plan.
Currently I pay $59.95/month for an AT&T Data Plan with a Data Connect card but that card only will work with our laptops on the go. I was at Best Buy tonight looking at the iPad and came across two options, Verizon's MiFI service and Sprint's Overdrive service. It seems Sprint offers two devices.
I have always heard that Verizon is much better than AT&T but also that Sprint was inferior to AT&T or Verizon.
After talking to the salesperson, she said Sprint is the best service out there, better than Verizon or AT&T. I told her I had heard that Sprint isn't that good and does not have the best coverage. She said that's true for voice but not for data and for data Sprint has the best coverage and also Sprint is now switching to 4G in many cities which is of course faster and that where we live in Denver it should be done by the end of the year.
From the information she gave me it appears both Verizon and Sprint charge $59.99 a month for their services for 5GB, the same I pay for AT&T. According to her Verizon is moving to 4G but likely early next year in this area and Sprint is currently upgrading but according to her once Sprint changes to 4G the service will drop to $49.95 a month and also the data plan will change from a 5GB limit to unlimited data.
Has anyone heard anything about this price change or unlimited data?
I have several questions below:

-How does the speed of these compare to a USB dongle. I know it's the same network but being it's over wi-fi and not a connect direct, is the speed any slower?
-What kind of range does the wi-fi network have, especially for a good connection and speed?
-Is Sprint's coverange, network, and speed really that good?
-Between Sprint and Verizon, does one stand above the other?
-As stated above, is the information about 4G (release dates for Verizon and Sprint) and the change to unlimited data or a decrease in cost true?
-Does either of the units offer the ability to block certain websites? For example if her son uses his ipod touch on it could we block sites like Welcome to Facebook, MySpace, etc. so he can't access them. I know it would block us also but that is fine.

Thank you for your help with the above questions.

IMO, the iPad is pretty much useless without a network connection. The only app that would work for me while offline is iBooks, my Task & notes apps, but even then those all need to get synced at some point to ensure my data is backed up (and to buy new books).

That being said, I don't really see how you think you are saving any money if data plans from all three companies you looked at are right around $60/month - it's only $29.99/mo for unlimited 3G from AT&T, so if you and your wife get 3G iPads, you end up paying $60/mo.

Sure you have the higher initial cost of the 3G iPad, but that's a small price to pay for the convenience, IMO.

Also: I've not really done much research on those MiFi devices, but what's the battery life on them? The iPad has been proven to have at least a 10+ hour battery life; will your MiFi device keep up with that?

The 3G model is projected to have about 9 hours of battery when running on the 3G data network.

Do you really want to carry around your iPad, its charger AND your MiFi and its charger too?? I sure wouldn't.

As far as the networks themselves, Verizon & AT&T are both very good. I personally have never met anyone who has been anything other than quite UNhappy with Sprint, on the other hand.

As far as the range of those MiFi devices, I'd imagine it's right around 15-30 feet or so, IIRC.

With how slow current wireless broadband networks are, I highly doubt you'd notice any difference at all between a MiFi device or a USB dongle.

I don't know if you can block sites on a MiFi device or not, but if you can, I'd be curious to see whether that would work to block access to the apps or just the websites, or if there is any difference between the two....

I'd just get two 3G iPads, man.

In regards to Sprint's 4G network and the prices/data limits, I don't buy it. It makes NO sense at all that they'd spend millions and millions of dollars on a 4G network and then DROP their prices and REMOVE data limits. Makes no sense whatsoever.

I don't think any real 4G network is going to be fully functional across any significant coverage area in the next 5 years.... maybe a city or two here and there, but nothing major.

What you said sounds right about the ipad. $130 is a lot but overtime it would pay off. Like you said it would be the same as the $60/month plus unlimited instead of 5GB limits and not an extra unit to carry around.
The only issue is about every 1-2 months we take a 1 week trip to a relative. We both work at home so are able to do this but since we have internet businesses we do a lot of internet/computer work. There's no wi-fi at this location so we both take our macbook pro's and currently share the aircard between us as we do work. If we were able to simply use the ipad only for our internet use we'd be fine but I'm not sure if that can be done so it would leave our laptops without internet. We would end up having to pay $60 for both ipads plus $60 for the aircard for the laptops.
I have posted on some cell phone forums. I have seen more post in favor of Verizon but Sprint but some claiming that Sprint has improved. What I don't buy either, it seems with Sprint you get 3G with a 5GB limit for $59.95 a month or you get 4G when available and when you use that it's unlimited for $59.95 a month.I don't undersatnd how faster data is free. It just makes no sense.

Another thing to consider is that there is no contract with the 3G data plan from AT&T for the iPad, so you don't even have to consider it a monthly expense if you won't be using it enough to justify purchasing it every month.

There is also a $14.99 option for 250MB of data per month, again no contract.

It's the network - Really - Have Verizon Mifi - Works great.

4g coverage is unlimited right now. And its speed is average 2mb-5mb with peak at 10mb for downloads and .5mb-2mb peak 5mb for upload.