I play cross-platform. I leveled up mostly on my PS3, but now I mostly use that for gathering.

As I see it, pros/cons of each:

PC
+ More shortcuts available on the hotbar.
+ Quicker target selection with mouse if needed.
+ Quicker drop-targeting AOE reticles with mouse.
+ More options for play-style (kb/mouse;controller;monitor;tv;etc.).
+ Potentially higher graphics settings.
+ Ease of VoIP use.
- Expensive real-life investment.
- Potential for occasional hardware/software issues.

PS3:
+ Cheaper real-life investment.
+ Game optimized for the system.
+ More potential for comfortable play-style (some people can't/won't setup their PC's in a living room).
- VoIP require 2nd device.
- Lower graphics settings.
- Locked into crossbar usage.
- Keyboard use potentially more awkward.
- Requires tab-targeting.
- Slow/awkward drop targeting.

Some of those items are personal. You might be a pro at drop targeting your aoe reticle; I could never get used to it in 50 levels. You might have an awesome PC room with super comfortable chairs that blow away your living room. Who knows. I think there is greater potential with the PC, and that's absolutely part of the design philosophy of this game. PS3 always will be the lowest common denominator when it comes to designing mechanics and game architecture. I think PC users should be thrilled the team is supposedly building a Direct X 11 version of the game, as it will give people who love making high-end PC's something to go crazy with. You should never need a high-end system, though, to tackle any game's mechanics. That would just be poor design from the start, as there would be much too small of a market for the product.

Overall, I think SE has done a smart thing by catering to multiple audiences. I believe we will run into far fewer "PS3 limitations" problems over the next few years than we ever did with XI. Even many of those issues were worked out by the development teams in time.

To be perfectly frank, the people that are screaming about the PS3 holding the game back strike me as the kind of players that will move on to a new games quite quickly because newer games will likely be "better" in the ways they seem to care about. Fighting to keep such people in the game may be an exercise in futility.