Why not use TFS as a build / CI solution?

Currently our build solution is set up using TFS + MS Build scripts.

TFS is also being used as a CI server.

I've seen several posts on this site telling people about other CI solutions. Are there any compelling options to move to another Solution for our build system?

Or in other words what are we missing out on by using TFS?

EDIT

We are using TFS for source control / issue tracking and I think this is a good solution, im just wondering about the other options for build server / CI server integrating with TFS.

The main problem with TFS is that if you have a server crash, restoring your source code is non-trivial. This is unbelievably bad since the most important aspect of any source control system must be to be fail-resistent, at least if you perform all backups as you should.

IMHO the greatest benefit of TFS is that everything is integrated in the IDE: work items, bug tracking, CI, Code analysis, ...

I have used TFS in the past but my current company use SubVersion/Team City/FogBugz to implement the same functionality provided in the TFS solution.

I would say that from a technical implementation perspective, you can gain additional features from a non-TFS system that TFS would be a nightmare to configure.

However, that said, one of the biggest reasons for not going for TFS is the cost of running such a system. The big advantage of TFS is the integration of everything which makes people use it more as the more you put in, the more you get out. The worst case scenario is a system that people can’t be bothered using which adds no value to the company’s development.

In my opinion, if you are already on TFS and can afford to stick with do, do just that!