Also, make sure that all of your body straps are tight and secure…

Husqvarna 350BT vs 150BT The smaller tube diameter of the 150BT allows for quicker speeds. The 350BT, on the other hand, has a higher CFM, which is a measurement of volume rather than speed. The 350BT can blow greater piles of leaves than the 150BT because it moves a higher volume of air. A 150BT, on the other hand, may make it easier to blow out microscopic cracks since the air is propelled faster. What you do with it is entirely up to you.
I’m sorry your new blower is giving you trouble. Because it’s our most popular model, finding out you’re experiencing trouble with it is upsetting. The Husqvarna 150BT backpack blower’s vibration dampening system is meant to reduce vibration. Also, make sure that all of your body straps are tight and secure. It’s conceivable that the idle speed of the carburetor has to be altered. Before making any changes, make sure the air filter is clean and the air filter cover is in place. The idle speed is set at 2200 rpm at the factory.
I’m not sure what “soft grip” means… The on/off switch and power trigger are on the normal grip, which protrudes out. And, yes, it can be changed. There is a little built-in screw on the side that allows you to adjust the handle. I hope you find this information helpful. I own both an Echo and a Husqvarna. Each one is backed by a one-year warranty. Both work flawlessly, and I am pleased with both. My Echo is about 3-4 years old and responds to a few tugs. Husqvarna just got it, and it starts right up with a couple pulls.
CRUISE CONTROL: A variable speed throttle with cruise control may be set for easier handling.
The operator’s cushioned harness and hipbelt are custom-fit to his or her proportions. Full blow force with minimal arm strain: The offset handle enables adjusting the blow forces simple. Keeping the arm from dangling downward Lowvib: Dampeners between the engine and the chassis effectively minimise vibrations. The idle speed is 2200 RPM. Cruise control: A variable speed throttle with cruise control may be set for improved handling. STOP SWITCH FOR AUTO RETURN: The stop switch is quickly reset to the ON position for simpler starting. HIGH AIR VELOCITY AND VOLUME: A powerful cleaning performance is provided by 434 CFM Air Volume and 251 MPH Air Velocity.

https://litecomparison.com/husqvarna-350bt-vs-150bt/