Smudge has a Kindle Fire tablet. This gives him access to books, games, and movies (for flights). It can be locked so he only has access to appropriate content and for a specific amount of time. Unfortunately, I don't really know much about the other tablets you mention.
We have a Nexus. Mostly it is Mr. S's toy, but the boys use it a lot too. My kids are a few years older than yours, but they love the tablet and use it to look up stuff for homework, to play games, and Mr. S has started N on programming with it. It runs Android and there are lots of educational apps you can get for it.
My parents have an iPad, I have a Huawei MediaPad (7" Android) for work which Ebay is no longer allowed to touch but O can), and our android phones. All of them have been great for games and entertainment, but using it counts against their daily screen time allotment.
I bet you can find a used iPad for affordability. http://tech.yourway.net/kid-friendly-ipad-cases/
Whatever you do get, invest in a screen protector. That's why Ebay is no longer allowed to touch my work tablet.
I admit, the family is addicted to our tablet......s. Yes, multiple tablets. Who are we kidding....multiple iPads. We fell off the wagon hard. No one really watches the television anymore, except maybe my (geriatric?) husband who watches NCIS.
It does count for their screen time. Both boys (2 and 5) work the iPads mostly on their own. The older boy has a whole slew of educational apps that actually DO seem to have made some difference. The younger boy likes to do anything older boy does, so he launches Angry Birds in the wrong direction for 10 minutes and he's good to go. He also likes to listen to the Mighty Machines theme song on repeat off YouTube. Wheels on the Bus...you get the picture.
You know the montessori philosophy that implores parents to use REAL tools? Like real saws to cut, real scissors, real hammers? I feel this applies. The leappad, the innotab, those are toys. Your kids are going to see right through them and leave them in the dust like every other product from those companies. Get them real tools like the Nexus. We've had our oldest iPad for years now, so imagine the life span of something you get now could definitely last them until they start to have to do real work in school. Also, love Google translate app for your bilingual kids! It was a lifesaver when I got a non-English speaking French student in my class last year. I spoke into it, and it came out French...usually correct French!
We've done pretty well so far with content. The oldest definitely is alone on YouTube at certain points and he's been very good about coming to us the second something "weird" or "for adults" comes up. That may not last, but I'll take it now:).
Also, Otterbox the hell out of it. I got my disabled mother an iPad (changed her LIFE), and she dropped it and I had to get another. OTTERBOX.
They will fight over it. What's new?
First Kid has a Google Nexus.
As far as parent control over content the Google Nexus has been awesome. I can set an admin account and additional users. I can set the maturity level of what he can view on Youtube, what apps come up when he searches, and also control his spending (he has his own Gmail address and it has Google Play credit). First Kid uses Google Documents for homework and it is nice that even he can't get on the computer when he is at Former Companion's house he can get on his tablet and continue whatever he was working on.
The thing that I most enjoy about the Nexus is that I can log onto any computer anywhere add any application, movie, music, or book to the tablet that I want. I never have to hook it directly to my PC.
It is also nice to be able to have Kindle books, Google Books, Google Music, Amazon Mp3, Google Apps, and Amazon Apps to purchase from. Second Kid has an iPod touch and it sucks to not have more options that Apple to buy things from.
I second, third, and fourth the Otterbox.
Additionally, you can get two Google Nexus 7s for the price of one iPad.
This whole thing makes me want to cry. I wish I lived in Little House on the Prairie. Seriously. I can't keep up.
P.S. OTTERBOX: Because when you think hardware safety, you think big, cute rodents.
Agreed with Bap! Tablets, iphones and the alike are only growing and expanding technology... they aren't going away any time soon (sorry O!) I like that El D is capable of watching videos, playing games... and understanding how it works... "hey, mom! download this app for me later, please?" He gets it. That part is awesome... because El D was slightly obsessed at first with games, etc I set limits... timers, warnings (5 more minutes!), etc... but I'm actually happy to see him self regulate more now...
Anyway. I say do it. I like my iPad only because work gave it to me. Ha! But I was looking into the Kindle Fire and the Google one for the 'at home' tablet.
I agree with bab2 and give them real tools. We like the Kindle Fire. It gives access to books and Amazon offers a bunch of free (kinda cheesy)kids books. It also has some really good drawing apps, some that are accessible to my one year old. My kids love it.
My friend has bought the 'LeapPad' for her daughter - there's loads of educational games on there that would be good for your kids. It depends on your budget though, I think the first model s around $79 and the updated one around $20 more.