I really like fighting against bots as much as I do against other people, and I think the idea of an instant action button is a good idea
in general.
The problem is it is not implemented in a very interesting way- always 3 or 4 bots with a below average skill level, always deathmatch and only on a select few maps it seems like.
This is so repetitive and boring that I didn't like it when I first started playing Nexuiz as a newbe in 2.3 and I find it the same way now that I'm used to fighting "Pro" bots.
(I only have a 15" screen atm, on bigger screens I find even Pros are actually cake, since I can see them then and they won't use cover.)
What would make Instant Action worth keeping imo, is for it to have access to almost every bot setting, gametype, map and mutator that ships with the game, to be used at random. 2 Botlikes on Ruiner Deathmatch one match, 1 Godlike on Silvercity Domination with Grapple Hook Mutator on the next match, 6 Experts on Dieselpower Keyhunt with Low Gravity (75%) on another match, etc.
So much random goodness that it never gets old. Kind of like a dynamic campaign mode.