Blazed Out.... there's some useful reading here:
http://www.mellowgold.com/grow/mjbotany-removed/
It's from Rob Clarke's book.
I agree that the general consensus is to cross an indica to a haze variety as well. However, one CAN cross two similar varieties. I'm guessing the only problem that this might pose is in Combining Ability.
The ONLY way to select for combining ability is to test for it.
Even though there is a positive relation between overall vigor of an inbred, and the yield of its crosses, the combining ability is more important.(Clarke)
So, if I'm interpreting this correctly, the idea is that when combining a haze with an indica, one stands a better chance of inheriting noticeable characteristics from both. However, when combining a haze with another sativa, it is less likely that the majority of the progeny will show characteristics of both of it's parents. Statistically there would still be some progeny that show a good combining of genetics from both parents. It's just that one would have to grow out many more progeny to select from since the combining would show in fewer of the progeny.----This all ASSUMING I understand this correctly.
So in short, if one wants to make selection somewhat easier (for taste, for instance) then it would make selection easier if one crossed the haze with an indica due to the better combining ability of the two.
I will most likely do this first, as a learning experience. Maybe O. Haze x Joey Weed's Sugarberry. The idea would be to increase the potency of the SB, while keeping it's syrupy-sweet taste.
Once I have a better handle on selection, I'll attempt to increase the potency on a sativa-dom. All without losing the other necessary traits of a solid strain...no herms, mold resistance, etc.
As a side-note, I want to stabilize each of these past F1. F1's are ok, but I'd rather have the strain(s) produce a consistent two or three phenos, if possible.