What nuance does "ですな" bring?


I often see ですな used in social text posts.  
[Examples](http://live.nicovideo.jp/watch/co1780853):

> こんにちわ、あついし、ひまですな。
>
> いいてんきですなｗ

A Google search for "ですな" does not show me any explanation.

Here is how I understand ですな in such context:

  * Humourously "aristocrat"-sounding.
  * Auto-derision of fake deepness.

Am I getting it right?

Why would someone use "ですな" rather than not use it?  
What nuance does it give to the sentence?




ですな is a version of ですね and is decidedly masculine speech for males over 40
(would go well with わし, for example, but can be used on the internet as a joke
by anyone, of course).

There is also

> いい天気ですの

or, even better,

> いい天気じゃの

which is even stronger than ですな in the sense that it would really only be used
by males over 60.

The ageless equivalent is ですね in all cases.

P.S.: ～ますな has the same nuance as ～ですな, whereas plain form + な is decidedly
less restrictive. 食べたいな, 面倒くさいなぁ, よく食べるな, etc. can be used by anyone,
regardless of gender or age.

