The T300/TX is approximately 75% more powerful than the DFGT in pure wheel test spin speed testing. But it's also much smoother, much easier to turn the wheel, and the motor doesn't get in the way when drifting like it does with the DFGT. t300 pedals are also better: longer accelerator throw, and the brake is firm enough that you can lean on it, unlike the floppy DFGT pedal which shows 5% if you so much as touch it. I can't think of a single area where I'd prefer the DFGT over the T300 (with the nice metal rim), since personally I loathe the cheap nasty sequential stick on the DFGT and never dared to really use it since I was worried it would snap.
For reference, the DFGT and G27 rims are both 27cm diameter. The TX/T300 are 28cm diameter. The Fanatec Porsche wheels and T500 are 30cm diameter.
What does smoother/stronger mean? Well smoother means you don't feel the cogs grinding together as you turn the wheel. Stronger means the kick from hitting a kerb or bump is greater, the force trying to center the wheel in turns is larger, and most importantly it can spin the rim faster. This is relevant any time you have oversteer, since in a real car the front wheels try to follow the direction of momentum of the car if you let them, so as the back of the car pushes out the wheel should turn automatically to follow the front wheels. A low powered FFB motor can't turn the wheel rim fast enough, so you end up with the game trying to simulate oversteer but the tools (FFB wheel) not able to do what the game wants. The more power you have in the FFB motor, the closer to simulating real car behavior you get. Obviously the T300 or T500 have their own limits, but they do get a lot closer and you can let the wheel do it's thing much more than with a DFGT where you need to help the rim around to avoid spinning the car during oversteer.
Having said that, if you are happy with the DFGT, why upgrade? Enjoy the wheel, buy more race sims instead of a new wheel.
(I say this as an owner of the DFGT, G25 and T300, btw)
I agree the TX is an upgrade in every way over a DFGT, but I don't think it's worth the money over a G27 at £150. I'd say maybe get the TX/T300 if the G27 was the same price.
The TX/T300 start at £220-£250, but to get similar pedals it's another £100. Now you've got three pedals you may as well get a shifter like the G27 has, that's another £100. Later on you think the wheel feels cheap and you want a leather rim, just like the G27. That's another, you've guessed it, £100! Even if you don't want the rim or shifter, you've spent over £400. :o
The price for wheels is high, but the price for some accessories is crazy.
The main problem for me, is the TX and T500RS are far too expensive for what they offer. The noise and friction of gears is annoying, but the belt drive wheels cost far too much for what you get. Also it seems like they are more likely to go wrong outside of warranty.
You buy a G27 for £150 in the UK. That's a good deal if you can tolerate the extra noise and friction of gears, as the pedals are decent.
You said 'the motor doesn't get in the way when drifting like it does with the DFGT.'
I think the motor gets 'in the way' on all the FFB wheels, as the reaction time is too slow due to motor/wheel inertia.
I think it's not possible to get a fast response without using a direct drive wheel, as the motor is spinning too fast using any kind of belt or cog gearing.
We need hydraulic force feedback, or a direct drive wheel, to get close to real steering.
:o
You also said: 'The more power you have in the FFB motor, the closer to simulating real car behaviour you get. '
It depends on the car, but I think a lot of people have far too strong force feedback. I know it's easier to sense the tyre grip level, but it's not right on a road car.
With power steering you need a force of about 4-6nm when stationary, and far lower when rolling.
The G27 produces 3nm, so it's ok for simulating any power assisted road car. It's only high downforce racing cars, that have a really high steering effort.
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