ITunes M4A vs Amazon MP3, ripping in iTunes, cloud services

Question

Sorry to ask 3 different questions in 1 thread, but they're all kind of related..
1) I've been struggling for a while to decide which service to use for digital music. Until recently, I always bought physical CDs and ripped them to my computer at 320Kbps. Then, Amazon started to attract me with all of the deals they have and free credits, not to mention the Cloud player. So I started buying from Amazon. I also had some iTunes credit, which I used and was surprised to find quite a difference in quality. Both are 256Kbps, but Amazon uses MP3, while iTunes apparently uses AAC M4A files. The thing that stands out to me is that the audio is louder and clearer.
Has anybody else noticed this? Everywhere I look online people say there's no difference in the two, but I swear there is. If you download the same song from Amazon and iTunes then listen to them back to back at the same volume, you should notice the difference. Preferable some kind of rock song with louder music where it may be a big harder to make out the lyrics. It's not so much "quality", like the MP3s sound "bad" compared to them, or are missing parts of the audio. It's just that the M4A files are louder and seemingly clearer, making it easier to understand lyrics. It's different than just turning up the volume, the words really stand out more in an M4A file.
So is it just me, or is AAC really that much better than MP3? The 256kbps M4As  from iTunes even sound better than the 320kbps MP3s I've always ripped from my CDs via Windows Media Player. I've not, however, compared to the 320kbps MP3s from Google Play, maybe I will try that sometime.
2) Assuming that it's better, that means I need to re-rip my entire CD collection. Will ripping within iTunes to M4A 256kbps give me the same quality as if I bought the file from iTunes and downloaded the file? Also, it looks like you can rip all the way up to 320kbps. Is it even worth it with AAC files, or will I likely not notice a difference over 256kbps?
3) Finally, cloud services. This is the one that has me the most confused. I have 2 goals really: #1, be able to listen to all of my music on my work computer in addition to my home computer and #2, have access to all of my music in some cloud service to access on my Android phone and Android tablet. I have 3 main services to chose from, Amazon, Google, and Apple, each with pros and cons.
Amazon
Pros - lower prices, lots of sales and free credits, all MP3s purchased there are automatically added to my Amazon Cloud, as well as any albums that have the "AutoRip" feature, Amazon Cloud Player seems sufficient both on my desktop and mobile devices.
Cons - lowest audio quality out of all services, can only store 250 personal songs for free, $25/year to upgrade to 250,000 songs
Google
Pros - lower prices than iTunes and sales, but not sure if they're as good as Amazon, all MP3s purchased there are automatically added to my play library
Cons - the desktop web client and mobile app aren't very good, IMO. You don't have much choice over how to view/organize the music. Amazon Cloud player seems better in every way.
iTunes
Pros - best audio quality, iTunes Match for $25/year to have my entire iTunes library in iCloud, including songs not purchased from iTunes (no size/# limit that I'm aware of), iTunes desktop app works fairly well and could be installed on my work computer and play my entire library with iTunes Match
Cons - highest prices, no client for Android devices, iTunes Match costs $25/year
(if I left off any pros/cons, please point them out and I'll add them to the list)
So here's my predicament: I want to start ripping all of my CDs and making all of my digital purchases in iTunes, mostly because of the superior audio quality. But, doing it this way I'll have no good cloud option for my phone and tablet. I could pay for the Amazon Cloud Pro to be able to upload my entire library there, but I would lose the quality of most files (they would match the files with their versions). I could upload my library to Google Play, but I would lose the quality there as well AND I hate their web client and mobile app.
Alternately, I could start purchasing all of my stuff from Amazon. Then, I could pay for iTunes Match to upgrade all of my songs to the better quality files, but I still couldn't use it for cloud-purposes, and it seems the only way to get the files onto your computer is to delete the source file then download it from the iCloud, but a lot of people are saying that's risky.
So, I just don't know what to do. Is there something I'm missing here that would offer me a better solution? I wish Amazon would just start offering better quality audio files, that would solve everything.
Note: I'm aware I could just store my music ON my Android phone and tablet, but 1) that would take a lot of manual work and upkeep and 2) I wouldn't have enough space on my tablet for my entire library (or on the phone without buying a 32GB microSDHC card). So, I really don't want to go that route.

Answer 1

AAC is a more modern codec than MP3 and thanks to advances is able to be more efficient at compressing audio than MP3. This means that at the same bit rate e.g. 256Kbps AAC will retain more of the original quality than MP3 at the same bit rate. Most of the articles I have seen say that roughly a 256Kbps AAC file would be equivalent in quality to a 320Kbps MP3 file meaning the AAC file is up to 25% more efficient.
You could if you wish rip CDs at 320Kbps AAC and that in theory would sound even better compared to a 320Kbps MP3 file. However for most people listening on a portable media player (aka. iPod) with standard earphones you would not be able to tell. In a home playing through your HiFi speakers then you might be able to tell the difference.
By the way, it is now possible to rip all your CDs in Apple Lossless format meaning it is exactly the same quality as the original CD, and still have iTunes automatically convert to AAC when copying to your iPod/iPhone. This way you get full CD quality in your home, but use a smaller slightly lower quality file on your iPod/iPhone.