My pleasure. I can elaborate all you want!
Sure, every rom has ups and downs, and I did not choose FR over else for this, since Emerald has more 'ups'. It doesn't have to do with ups and downs, if you're not looking for something in particular, but rather a ROM to hack. So, leaving aside any game with words (I'm referring to the people who want to play with the word 'hacker'), I think that Fire Red is easier to hack compared to Ruby and Emerald, for three reasons so far:
1. Tool variety. Yes, unless it slips your mind often, there are many people, like me, who would like to base their project more on tools than advanced methods (ahem), and most of these tools are designed, or at least, have a better approach to Fire Red. I don't know what led to this, but the way it is now, Fire Red is supported the most.
2. Tutorials. If you read my journal, then you know that I have been learning so fast without exactly relying on tutorials. However, if I would do so, most of them are like tools; they support Fire Red more than the other ROMs. Tutorials that I see fully supporting R/S are mainly graphic editorials-because, well, truth be told, I went to WAH and saw that people are mostly hacking Ruby for graphics nowadays-and for Emerald, uh, I suppose I should describe it as America, four centuries ago. Already known to the World, but a select few are daring enough to tread over it. You being one of them, I suppose?
3. Interface. I assume that you can say here that this is an excuse, since one can transfer most of the FR graphics over to any of the other two roms, but forgive me while I say that this is a waste of time, because after all, the fullest of interface can't be transferred (yet).
Finally, allow me to say that one might want to stick with what he grew up, and in this occassion, some people prefer to stick at one rom, than exploring all. I believe that this separates the sole-purpose hackers from the multi-purpose ones.
Back to you, I hope I 'spoon-fed' you enough arguments to understand that I find no further complications in choosing which rom to hack.