For years I was using CVSNT client to work with Firebird and any other CVS repository. I started to use it because I needed a client capable of handling the "sserver" protocol method, which the "standard" CVS can't.
A first thing I've noted has that it most times refetches completely (or just crashes trying) Firebird ChangeLog file during updates because some "corruption" (supposedly because it has more than 2MB). But that was OK with me, I just press Ctrl+Break and continue working.
By some reason, I had to use Cygwin's CVS to checkout whole firebird2 tree. It was much faster. So I switched to non-NT client and anything is much faster with it.
I've just started a merge of HEAD in my branch now. A lot of conflicts to resolve, most of them related to cleanups and formating changes. Unfortunately, it can't make this faster. 😃
BTW1, to open all conflicted files in gedit, I'm using:
<div class="remark-highlight"><pre class="language-bash"><code class="language-bash">grep -RlZ "&#x3C;&#x3C;&#x3C;&#x3C;&#x3C;&#x3C;&#x3C;" builds/ src/ |xargs -0 gedit
</code></pre></div>
BTW2, CVS is dead. Who cares?
BTW3, GIT seems excellent, but is somewhat difficult to grasp.

CVSNT client is slow