I ordered 8 of RED and 8 of GOLD Power HD Storm35 High Pressure Brushless Servo 35KG Metal Gears
The spec is great and I have been using the Storm 4 servos and B4 and 5 servos for a couple of years with no problem. For the speed I went with the S35
I see no reason to get the S25.

If you order more than 2 they are $88 at banggood.

https://www.banggood.com/Power-HD-St...r_warehouse=CN

https://www.banggood.com/Power-HD-St...r_warehouse=CN
https://www.aliexpress.com/i/4000185511360.html
https://www.ebay.com/itm/Power-HD-St...70wHLspLSbWCng
Description:
Item Brand:Power HD
Item Number:HD Storm35
Item Name:Servo
Material:Metal and plastic
Color:Red,silver and gold(optional)
Product Size:40.7 x 20.5 x 38.6 mm ( 1.60 x 0.81 x 1.52 in)
Product Weight:About 75g
Fit For:RC Vehicles Model

Specification:
Torque(6.0V): 26.0 kg-cm (361.1 oz/in)
Torque(7.4V): 30.0 kg-cm (416.6 oz/in)
Torque(8.4V): 35.0 kg-cm (486.1 oz/in)
Speed: 0.095 sec (6.0V) │ 0.075 sec (7.4V) │
Speed: 0.070 sec (8.4V)
Operating Voltage:6.0 ~ 8.4 DC Volts
Bearing Type:Ball Bearing x 2
Motor Type:Brushless Motor
Gear Type:Titanium & Steel
Operating Temperature: -20℃~60℃
Working frequence:1520μs / 333hz

Features:
Full cnc metal high-grade oxygen shell,three colors for you to choose
7075+303 imported steel gear
Japan NOBLE potentiometer
High pressure brushless motor,compatible with 6.0-8.4v voltage
Upgraded PCB, support SSR, SUR super high speed mode

Package included:

What plane did you install the B4, 5 servos on? Are they as good as the manufacturer's descriptions? Thanks.

Originally Posted by ERICKUO

What plane did you install the B4, 5 servos on? Are they as good as the manufacturer's descriptions? Thanks.

Yes they are and they are fast too. They are over kill. I used them in a giant 30cc stick. Still as good as the day I put them in.
I have the Storm 4 V2 in a 60cc plane and they are smooth and no slop.
When I seen these new S35 I had to have them. They are going in a Extreme Flight 120" Turbo Bushmaster
and Extreme flight Extra 300
I like brushless for the lower current draw. Uses only whats needed.