Key differences:

There's a 2-seater planned for the T-50;
The T-50 has a slightly larger (78.8 sq. m. against F-22's 78.04) and better-loaded (330 kg/sq. m. against 340, max. 470 vs. 487) wing, which makes it more agile in dogfight, combined with...
3D thrust-vectoring engines (Saturn Make 117 - no official name for the engines, they're still referred by development code) - the F-22's engines are 2D-vector only;
Improved radar signature, claimed to be smaller than F-22's (0.3-0.4 sq. m. in centimetre-range radar waves vs. F-22's 0.4-0.7);
Higher thrust:weight ratio (traditional for Russian fighters) - 1.19-1.38 combat-loaded, 0.84-0.97 max. weapons+fuel load/max. weapons load (1.17 combat/0.88 max. load for F-22);
Higher internal fuel load, 12500 kg., allowing the T-50 to work as a long-range interceptor with a high supersonic dash speed;
Higher maximum airspeed - 2100-2600 Km/h depending on altitude (most planes can actually go faster than their maximum rated airspeed, but at the risk of airframe damage);
Lighter than the F-22 (yes it's larger, but it also weighs less): 18500 kg. empty (F-22's 19820);
Higher max. G-load (10-11 g against 9.5 for the F-22).

If anything the performance is bound to be improved - the numbers are given for the T-50 prototype, not the production version (compare the T-10 with any Su-27 production variant).

Overall it's pretty similar, but the T-50 is designed to be an agile dogfighter with 3D thrust vectoring, a concept the USAF has forfeit. It has fully mobile fins (whole surfaces move, there're no rudders).

T-50 & Su-35 parked. Notice the fully rotating fins.

RH-50 are Roland's low-end studio monitor headphones. In spite of which they're quad-driver - they have dedicated tweeters which sound really smooth when the headphones are recabled. Great for saxophones and any treble-based delicate music. RH-50 are much like the K-240 with less detail and an even more raised midrange.

And AKG K-240 Studio are, well, what the name says - studio-standard headphones. Current generation (4th, 55-mm. diaphragms) is quite different from the original, if you want a suggestion, try to hunt down the original silver K-141 or K-240 Sextett (38 mm. diaphragms, K-240 are the circumaural version of K-141) and recable them, then give them a good amp.

You can mix in K-240 (many musicians mix/record in K-271, the closed variant), and frankly, the stock AKG cable is horrid. A replacement cable might cost almost as much as the headphones themselves, but it's worth it.

The final Su-35 standard has done without canards, thanks to FCS and engine thrust vectoring improvements.

Here it is taking off from the company's Siberian factory runway. Beautiful, isn't she?

Su-37 engine, 3D vectored thrust nozzle.