The sort answer:
Use the latest SVN server and SmartSVN (the community edition is free) as a client.
You will not pay anything and you can get everything you need.
The gory details:
BTW the feature of imposing the change management rules during checking is trivial to write as a SVN hook. We did it in a couple of hours, in one hundred lines (or thereabout) of code - it works wonderfully and never broke. It integrates SVN with Bugzilla and imposes rules such as:
- In order to commit you have to enter a message
- In order to commit you must have entered a Bugzilla ID that is in a "Valid" commit state.
... and so on, you can build your own rules to your heart's content
Accurev seems to be marketware to me ... lousy GUI client ... very slow (we had to upgrade the HW to make it actually work effectively), and of course ... you have to pay for it! Ah yes, if you do use it, I hope that you do not have to replicate your server between some place in the US and some place in India :)
Perforce is more robust but it is not very easy to administer. In any case, it is a superior product in comparison to Accurev.
VSS and stuff like that should not even be considered as "version control" systems when it comes to writing professional software (typically, enterprise software) in the 21st century. That's like writing your reports on a typewriter ;-)
If you know what you are doing (with your software) then SVN will be a robust and efficient solution for you. With (at least) two robust and efficient revision control systems in existence today (SVN/GIT) there is very little room to justify working with a proprietary solution; some reasons could be "inertia": you have it, you don't care paying for it, and you didn't have any major issues -- in other words, it works for you.
I use SVN everywhere, when it didn't exist I was using CVS, and before that ... no I am not going to tell you how old I am ;-)
Hope this helped ...
Ciao.
