Lead-acid batteries typically last well under a thousand cycles, and also deteriorate if you deep cycle them. Thus you'd probably need to replace a car battery solution every couple of years.
This isn't all that much better though. I don't think they have released the actual specs, but these batteries are likely to have a cycle life of around 3000 (which is consistent with the 10 year guarantee as they are unlikely to have a full cycle every day). This is much better than lead-acid, but as you say they are also much more expensive.