The mobile cloud is access to 10 sim cards at once. You will receive 10 different sim cards each one with different ip address.
When you buy mobile proxy you will receive ONE proxy, to have more proxies you have to buy more mobile proxy. When you buy mobile cloud you will receive 10 mobile proxy at once.
Yes, you can use maximum 100GB of data in one month (30 days). But the package is elastic. You can use it in one day, you can use it in 30 days, you can use it on one proxy, you can use it on 5 or whole proxies. The data package will finish after 30 days, the non used GBs will not be extended for next month. When you use 100GB before 30 days, you can buy additional 100GB transfer than new package.
In rotating package you will receive 10 sim cards. So you get access to 10 different ip adresses at once. But after 2 min whole cloud will reset and obtain new ip addresses from mobile operator, so after 2 min you will receive 10 new ip addressses. If a day has 1440 min and every 2 min you will receive 10 ips, you will receive ~7200 a day, not bad.
In full cloud it's hard to say, the same as in rotating plan the cloud will reset every 2 min, but your every query is made from different ip address, so basically if you made 50 queries in 2min, you will use 50 different ip addresses.
Please remember that we do not have influence what ip will mobile operator assign to sim card, sometimes the address may be repeated, or not change.
Basically you can use both clouds wherever you want. Those are normal proxies, but you have access to 10 of them at once, and they change ips all the time. But this changing of ips can bring some drawbacks. The proxy will be offline for 10 s every 2 min. Some of the proxies may not work during whole 2 min, after next restart. But here is not important, don't assume that you will have 100% connectivity. This is cloud, and here the main purpose is to make as many connections as you can from as many ips as you can. That is why using cloud in browser may not be a good solution. You probably will see that pages will not load, that there will be some timeouts. This is normal behaviour of browser, when it try to connect from changing ips. The best way to use cloud is to use script(php,curl,python), that can filter your connections, and do it much more faster that browser.
Sorry but we don't have cloud trial, the services is too big to just give a free access. But you can have one mobile proxy trial, if you imagine that you have 10 of these, it will be the same as mobile cloud.