Both the iPhone and Android are a pain in the ass to attach photos or other files. If I'm at that point with an email, that's where I put the phone down and pull out the laptop (or desktop). I also know that what I attach to my emails using a computer will arrive the same way (assuming I set it up right to begin with). I've sent pictures before on my phone(s) only to find out the recipient got links and not the hi-res pics I sent.I agree with phone calls and regular SMS but emails have gotten fancy enough (with images, attchments, etc) that they download faster when you have faster internet connection.
From experience (at work site), Verizon's great. With normal mobile use, feels like I'm on my home wi-fi most of the time.
AT&T is noticeably slower loading emails, websites, etc. I can watch streaming video but it often gives me issues when scrubbing (fast forward or rewind). Sometimes, it would time out while fetching email with the iOS Mail app and I'd get "This message is not available" or something.
T-Mobile can veer down towards unusable levels (e.g. like the 2G level speeds above).
But overall, yeah, I can agree with you on that.