To Addon, or not to add on?

This is a question that I've wrestled with several times throughout my WoW career (including on these forums - How much modding is necessary?

How much modification to the WoW UI is required for high-level game play?

I've done serious progression raiding as all three major 'roles' - first as a healer, then as a DPS, and most recently (and for the longest) as a tank. There's definitely major differences in requisite information to be effective, but I think there's an underlying common thread.

To begin with, the WoW default UI has evolved a lot. Forgetting recent advents, like the built-in threat meter or the recent addition of gear sets, there was a time at which the default interface didn't have raid frames, a LFG tool, and a variety of other major features. To say that the default UI is 'crap' now is doing a huge disservice to the extremely significant evolution it has experienced.

On the other hand, there is a huge amount of valuable data - and more intuitive ways to display that data - that the WoW UI doesn't capitalize on. From the old-school CT Raid Frames to present-day mods like Grid, there's been numerous attempts to improve upon the initial interface Blizzard provided us.

In my experience, there are three major camps of players when it comes to UI preferences:

1. The default purists. These people either don't want any mods, don't think the mods help, or maybe don't know how to mod. They use nothing except for the tools BlizzGod gave them.

2. The average player. This group encompasses most everyone who plays WoW seriously, as there's simply some things that the Blizzard UI doesn't do well enough, or lacks altogether.

3. The UI 'artist'. These players want their UI to be minimalist, or flawless, or aligned to the pixel; they want every trace of Blizzard's inadequate/obsolete attempts at design eradicated.

For myself, I've run that whole range. When I started playing, I was a class 1 - I wouldn't install anything. I made it through until Naxx 1.0 without having a single addon installed; the straw that broke the camel's back, funnily enough, was the guild that used a Rogue Evasion rotation to tank Instructor Razuvious between MC'd adds (don't ask). We had to know our precise* threat in order to plan out Evasions.

*If anyone remembers early KTM, using the word precise there is a blasphemy, at best.

I hit the class 3 'artist' stage late in my tanking career - in fact, it was more motivated by my push for Gladiator than anything. I needed everything to be in a specific location to react quickly and effectively enough to be competitive, and every mod that had the slightest issue come patch day was world-ruining.

Most people, however, are the class 2 - they use a handful of mods, either out of preference or as prescribed. They can play, albeit possibly not well, on a default UI (generally, a few quick video/interface/keybinding tweaks, and you're good to go).

I think it's fantastic that Blizzard opened the doors to all this modification and improvement, but I can also see the merits in a closed interface, where no third-party development is allowed - it's a lot easier to plan around for the developers, and it creates one less barrier to entry for newer players (since learning the default UI and learning how to build a rational, useful modified UI are two totally disparate beasts).

In Blizzard's new IP MMO, I hope to see a much stronger, more function-oriented interface. I think they can, and should, continue to allow for third-party modifications, but I hope that they will learn from how the WoW UI and the players' expectations of it have evolved to give us something that is intuitive, clean, and powerful.