Your email account will still be the same. You simply will not have access to the other iCloud options:
Basic Information About Moving From MobileMe to iCloud
I'm not sure what reviews you have read, but I've been using Lion since its release. I've installed it on six computers, four different models. I've not had any problems with it.
You can always install Lion on a separate partition or drive allowing you to test it out without compromising your Snow Leopard system.
Please note that if you migrate your MobileMe account on Snow Leopard your mail will stop working sooner or later. iCloud's mail server settings are different. Strictly speaking Lion 10.7.2 is required for iCloud, and on that Mail is set up automatically.
Snow Leopard cannot access most of iCloud's facilities, however you can set Mail up manually to access your email. The method is described here:
The situation with iCloud and Snow Leopard is described in detail here: