How do you judge/review your absinthe?
Should there be 2 reviews, 1 initially and one 2 months later?

I initially do it within the first few days of cracking the bottle. However, like wine, I've noticed that they're all different a month or so down the road. On the one hand, I think they should be aerated on day one and let sit at the back of a cupboard for a month an a half. On the other, I think an initial and follow-up reviews are important because some absinthes are awesome on day 1 and get even better after a couple months.

I know some folks will edit/update their reviews if their impression of an absinthe changes (or if a new batch/edition of an absinthe is released).

Not sure there's a need for one person to post multiple reviews of the same brand, if that's what you're suggesting.

I usually just post one review. It's been awhile since I have posted one. I need to get more involved (again).

New batch equals new review makes sense. However, some absinthes taste better after sitting in the back of a cupboard for 2-3+ months after being opened.

What I've always recommended is that people periodically update their reviews.

I recommend:

1) Keeping the original text, but adding a date footnote along with a notation of the original overall score
2) Add your new review above it, and use the star system for your new ratings.

See Leopold's review as an example.