I have used T300 for more than 2 years, and have had many issues with my wheel base, it has been disassembled around 10 times. I have done all the repairs myself, the big one beeing the adhesive replacement on the ferrite core (simple terms: reglueing of motor’s magnet (rotor) to main shaft of the motor), which is a pain, a massive one at that.
I have used firmwere v31, v33 and a couple of v2X, can not remember, don’t have old install files anymore. I updated the software and the firmware to latest (v34), here are my thought on the new update… I like the green, never loved the red, and it feels the same with the new boost feature OFF, maybe there are some differences (a bit snappier, sharper overall), but I, being a dumb meat-bag AKA human, can not feel them.
Now, the Boost feature – ON.
Lets all remember that the motor (B4260M) is still the same, the motor drivers (mosfets) are still the same. Firmware can not change that. Even if Thrustmaster decided to up the current (that is how to get more torque in this case, since belt/gear ratio is fixed) a bit on a device that is infamous for quality issues, you would still be left with a problem that more current = more heat, and the cooling solution is hardware fixed (fan + aluminium heat sink of motor). So I am going to assume that maximum torque of the wheel base has not changed (plus, release-note under Boost mentions "better feedback oversteer/understeer, enhanced road-holding, and optimizing steering system", no mention of extra torque or current in %, just terms that could mean anything). Than what does the Boost ON do?
I tested on Assetto Corsa, RBR(RSF), Dirt Rally, some others.
To me it feels like Boost ON is trying to maximize force feedback per corner in simple terms. With all settings in control panel the same, Boost ON feels stronger on same track and corner in the same car, but interestingly games report the same level of force (force feedback indicator in AC for example), yet the wheel is noticeably stronger/heavier. Which suggest to me that game is sending the same signal(requirement of force) to the wheel base, and than the wheel base is trying to upscale that signal(requirement of force) to produce more force, that happens to be closer to the maximum of what the base is capable of (set in control panel, lets say 95% for example).
And that is what I felt while testing, every corner felt kinda the same, gone were the heavy uphill corners, were car's mass transfer loads up the steering, gone were the light corners that do not take that much effort. Every corner had a bunch of force feedback, sounds bad, right? Well no, because of this increased force it is much easier to feel understeer/oversteer, it is much more pronounced, and easier to counter. If you are the "manhandle the car" type of driver, Boost ON could be for you. And in some games it could be "better" with Boost ON (maybe F1 series, have not played those much, but from what I remember). Just turn the force feedback either in Trustmaster Control Panel, or in game down a bit, because force feedback indicator in game might report incorrectly, and the wheel base will be clipping (not that all clipping is bad, if you sacrifice one corner clipping for more range in all other corners for example). So, sounds like a exchange: Boost ON gives more car force feedback, by giving less track/road force feedback, but…
I do not think that I can prove what I am about to say, to do that you would have to use testing equipment on wheel base or dig into the code of the software/firmware, but Boost ON feels weird on initial turn in, initial oversteer. If I try to describe it: the initial force feedback feels strong, but sluggish, slow and a bit dull then settles. On of the post on this thread mentioned this (slow oversteer or something), and I feel the same.
So test for your self, maybe you will like it, for me it is Boost OFF. Some games are just not right (RBR, but I have to ignore that one in overall discussion, too old, not well supported), in other games I can see the uses for it, if the initial force feedback weirdness is not noticeable. Call me out if you think I am incorrect, or missing something, these are just my thoughts and observations of of course.