I have used Virgin Mobile for about 3, 4 years.
Overall, I've been happy with them. I use them for voice calls and text messages. The coverage is good (they use the Sprint Network), I don't have dropped phone calls, and, AFAICT, I get my text messages about as quickly as they are sent. I like the way my phone works with my hearing aids and VM uses the CDMA network which is best for hearing aid users.
I would guess that the reason some people may not want to use them is because it's still a 3G network and there's a limited choice of phones. Also, there's the whole keeping up with the Jone's thing. I use a LG Rumor 2 and just the other week someone was ragging me about what an old-fashioned phone it was. :roll:
I think its a good idea to try them out while you can still return the phone in case you don't like it.
I do have a few reservations about VM:
1) Reaching a live person by phone is a real exercise in patience. VM wants you to use their automated voice menu system and if you have an issue that requires a person -- too bad. Whenever I call them, I only do so when I have time to be on the phone for about an hour and can use my speakerphone so I don't have to be glued to the handset while waiting for a person.
Their e-mail support is good -- but it takes about a day for them to respond.
I usually don't need "live" help, so when I do, I just suck it up.
However, because they are so difficult to reach in person, I decide not to let them bill me automatically. Others have reported on the web that they have been billed in error when they allowed VM to bill them automatically. So, just to be on the safe side, I pay manually.
2) If you use their pre-paid plan they send you annoying text messages to pay your next bill before your service expires, BUT your next expiration date moves up as soon as you pay regardless how much of a balance you have left. I find that annoying, but not annoying enough to switch over to a more expensive service.
3) This is probably more of an issue of the cell phones I have used rather than the service.
I've used a Kyocera, LG Rumor Touch and then traded down intentionally to the LG Rumor 2, which is my current phone.
I wasn't happy with e-mail on any of those phones. I had to manually check to see if I had e-mail, there appeared to be no way to get notifications. Since I didn't always want to check -- I stopped using e-mail on my cell phones. That, frankly, is something I'd be better off changing. I know I would be better off if I were more reachable by e-mail -- and I'm not always near my laptop.
I know that you can currently get a Blackberry or android phone that will work on the VM network. If you are still interested in VM, I would look up those phones models at the VM web site and then look them up at phonescoop.com Maybe e-mail works better on those phones. I'm sure it does on the Blackberry.
4) I find VM's pricing structure annoying; it's not as flexible as it use to be a couple of years ago. Now you have to choose between a pre-paid and post-paid plan and, AFAIK, you can't move back and forth between them. It appears that your telephone choice is restricted depending upon what plan you want.* ("Pay-lo" vs. "Beyond-Talk"). The pre-paid plan prices is not as inexpensive as it use to be a few years ago, but I do prefer to pre-pay on cell phone plans. I've seen people get into trouble quickly on post-plaid plans because you can easily go beyond your plan's voice minutes and get charged a high price per min before being aware of it. If you never use the phone for voice calls -- that obviously won't be an issue for you -- but I would be on the lookout in case they start doing the same for text, e-mail, or data-plans in the future. They can change their pricing structure whenever they want, although they do have to notify you first.
* The reason I don't know for sure is because the customer reps I talk to don't know for sure. I could go into this but its a long boring story and I would fall asleep before I finished typing it. I'll just say I got conflicting information.