i could be wrong but i think straight talk do not throttle the data speed at 8 mbps like AIO. also they offer 3 GB data for 45$
You are right about Straight Talk not throttling to 8 Mbps but it is a tradeoff. As this thread shows, Straight Talk does have a lower priority which means, depending on AT&T usage/coverage in your area, you could end up with slower speeds. AIO, from what I can tell, has a higher data priority meaning you should typically have very usable speeds.
From what it appears, part of the reason for the higher priority (beyond merely being owned by AT&T) is exactly because it is throttled -- they know that AIO users won't steal too much bandwidth from their postpaid customers. What I've heard from AIO customers is that they have great service -- 8 Mbps is fast enough for anything you need to do (including stream high definition video), especially since AIO delivers it consistently.
The issue with Straight Talk is the number of people that complain that they don't actually get 3 GB. Instead, if they use "too much" in a day or week, they are throttled (particularly since streaming video is not allowed per Straight Talk's TOS). I've also seen some people complain, when they are just under the data limit at the end of the month, that they get throttled near the beginning of the next month (basically, they used 2.9 GB last month and, after using 100 MB in the first couple of days they are throttled). The biggest problem is there is no way to get the throttle overturned; that is an issue customer service (including supervisors) do not have the ability to fix. Additionally, there have been numerous issues with Straight Talk users being unable to get MMS.
To me, there seem to be two items to consider. First, how much do you care about sometimes maybe being able to get over 20 Mbps, or do you just want good quality that is fast enough to do what you need? Second, how important is customer service to you? If you want fast speeds sometimes and don't care about getting customer service then Straight Talk is probably your choice. If you want good customer service to be there and help if you have problems, and care about having usable speeds rather than extra fast speeds, then AIO is probably a good choice.