I don't want to start another browser-war thread here... even though I'll use comparisons, so let's not do the predictable thing :¬)
Firstly, I like Opera - It's not my prime browser but I just wanted to straighten that out.
Some will argue that their market strength will come about because it's their core product and so can quickly churn out fixes/upgrades.
However, looking at the bigger picture I'm thinking that the quick succession of fixes/upgrades could, or is working against them.
Users in the wide world typically don't upgrade their browsers at the rate that Opera releases them.
Given that some of their older versions have rendering bugs, rapid and frequent releases simply means that there are numerous versions out there that're messing up our sites.
It's potentially adding - if it hasn't already - to confusion, ie... it's hard enough as it is to ascertain what will work in what browser and which version.
At least with the "drip-feed" upgrades offered by the likes of NN and M$ every few yrs, we, as designers/developers can invent/utilise workarounds with minimum fuss.
I dunno, I'm thinking it'd be better if all that had to be worried about was whether the site, and hacks, worked on IE, NN, Moz and Opera rather then the plethora of Opera releases <-- Simple comparison for sake of discussion.
All these new browsers coming onto the market lately just make me more paranoid.