RE: Himax 5300 Kv Motor
Do you mean 2025-5300 or 2015-5100? The larger 2025 motors are overkill and heavier and require bigger batteries... the high kv motors will work ok on 2s if you can really keep the weight down but also work ok with smaller props on 3s. You just have to lessen the load when using the faster spinning motors with 3s packs or else you can overheat some part or other.
For example, I have a 2015-4100 and 2015-5300 (the eflite equivalents) and I could run the 5300 at 6.6:1 gearing on 3s but had to go down to a 9 inch prop with a low pitch like a 9x4.7 as I recall... the 4100 on 3s can use an 11x4.7 prop. They both hover a foamy, the bigger prop on the 4100 is just more efficient doing it. If I tried the big prop on the 5300 I'd just burn it up in short order. The 5300 on 2S worked ok but could barely hover my plane because I only had older first generation 2s lipos. I'm sure current 10C rated 2s lipos would be better and I might try that. Then I could use the bigger 10 inch or whatever props on the 5300 and be lighter because of the 2s battery.
Hope that helps.