Recently, I started thinking that maybe I jumped the gun a little when I said I wanted to ditch deferred rendering. I came to this realization shortly after I started playing around with forward rendering and static lighting techniques. Ultimately, my findings with these techniques were not quite what I expected they would be, and forced me to reconsider my plans.
The difference isn't as apparent as I had imagined it would be, only really seeing a dramatic difference for distant objects. Even then, at 4x MSAA I am effectively paying the storage cost of a 4 MRT g-buffer. For that same storage cost, I could be storing information for dramatic post-processing effects, and complex lighting. Bottom line, aliasing is harder to notice in HD, and I expect it to become less and less of an issue as resolutions go up.
There are a variety of materials (SSS, anisotropic, etc) that really do need some kind of custom lighting in order to look their best. Sadly, I concluded that I really couldn't have many custom lighting models, since I would then have the headaches of a shader combinatorial explosion. So I have decided to settle for a good general purpose lighting approach that covers most materials.
Lightmaps and irradiance volumes have the potential to make for some stunning quality lighting. However, this potential is heavily dependent on the capabilities of the tools that generate and bake the lighting, as well as the processing power you have to perform the baking. The way I see it, if the maps don't have fancy effects (area lights, radiosity, etc) baked in, then I'd be better off with deferred shading since all the lighting would be dynamic.
Having had time to think it over, deferred rendering seems like the best choice for me. With that in mind, I need some new goals to help move my project forward, and decide where it ultimately needs to go.
In order to facilitate rapid-iteration, I will need to limit baking in my asset processing pipeline. Ideally, it will be limited to when the asset is imported into the dev tools, and when it is exported to the target platform format.
WYSIWYP is a must for modern rapid-iteration development, and this style seems to work well in the other sandbox editors I have sampled.
This will be a combination of different systems interacting. Between ambient conditions, post-processing, etc to create a mood and a world that feels like it is changing.
In order to fit with my deferred renderer, I will need a sufficiently capable shading model that can handle the vast majority of cases. It needs to feel like it covers a wide variety of materials, while not eating too much processing power doing it.
In conclusion, my little foray into forward rendering was a valuable learning experience, but ultimately didn't demonstrate enough merit for me to stick with it. So I will be transitioning back to deferred rendering, and don't expect to be moving away from it again any time soon.