1) The MKS HBL950 HV tail servo is awesome. I own two of them. However, I run them at 7.5v. I don't know how well they perform at 6v.
2) The MKS servos are generally deeper in dimension than the Futaba servos. See comparison below.
On the Synergy E5 and E7SE, you would need to shim the right and left cyclic MKS servos, otherwise these two front cyclic servos would contact each other at the butt end. The Futaba servos do not require shims. Those who use the MKS servos with shims do
not report issues with decrement in head geometry, so the MKS servos with shims should work fine.
3) I don't know about the
Scorpion 1100Kv motor, but the
KDE-1100Kv motor has plenty of power on 6S to spin 556/96 blades without bogging (specially now with the new Castle 4.18-KDE firmware). Decreasing Lipo size from 5000mah to 4500mah makes the E5 even more nimble.
Although there is improved electrical efficiency going from 6S to 12S, the weight of two 3300mah Lipos may make the heli loose agility when spinning the shorter 556 blades. Unless you plan on going with high C rated 6S 2600mah or even smaller mah packs, you may as well just stretch to accommodate the 606 blades, if you want to use the heavier 3300mah packs.
4) 2000 to 2350rpm HS may make choosing the optimal tail gear ratio challenging. When spinning 96mm tail blades, the optimal tail rpm is considered to be between 9,500 and 10,000. With the stock 4.0:1 gear ratio, the HS would end up between 2,375 and 2,500rpm optimal range. When using the optional 4.5:1 gear ratio, the optimal HS range would be between 2,111 and 2,222rpm.
Hope you enjoy your new E5 with whatever electronics you choose as much as I have.
