I've played the Dev Beta, and I'm neither impressed nor excited. The online component is required for gameplay, as the new engine offloads a lot of the simulation number crunching to EA's servers instead of the local CPU.
Yeah, the could saves and curvy roads are nice, but you're sacrificing a lot for that. City size is gimped, basic city sim functionality is gimped unless you build certain buildings - you can't, for example, start out building a sewage treatment plant, oh no, you have to dump sewage until you build the Dept of Utilities and THEN you can place the sewage treatment plant. EVERY city starts the same - mix of RCI, then slowly specialize while wrestling with the spacing of roads to have enough space for buildings to upgrade their density. It's not a terrible game, but there are more reasons to avoid it than there are reasons to buy it.