Cobra, unfortunately your not going to find an answer. If there was a definitive diet sticky that worked for everyone, we'd all be on it.
The best your going to get is anecdotal reports. I know Southern Lord gets superior results from high fat bulking; Tat is starting to try it. So some prefer high fat; some high carbs. Results will vary.
Mod/high carb bulking would seem better to me simply b/c:
- insulin is anabolic, and isn't a "bogeyman" when bulking for lean individauls (hence milk is a good bulking food)
- carbs are (at least IMO) the preferred source of energy for high intensity exercise
The contrary argument is that high fat bulking I guess would increase testosterone levels and lower insulin levels will mean less fat storage (still find this argument hard to understand in the calorie surplus context - it makes more sense to me in the cal deficit context because it will determine I guess the degree to which muscle/fat is used to fuel the cal deficit).
And if you are willing to spend the money, leucine is highly insulingenic and you could use a fair bit of it like Layne Norton does for its anabolic properties to negate the otherwise lack of insulin effect on a high fat diet.