Played 99 battles with a 69.70% winrate. Exceptional tank and really looking forward to the next in the line.
I played it like a mobile, good accuracy flanker. The turret rotation is very good so I would highly recommend the circle of death technique. Alpha is surprisingly good, averages around 180, so be aware that you can pack a strong punch in a fight. Reload is also pretty good so you can do some serious damage per minute.
Keep one eye on the minimap at all times. Wherever there are no tanks, go there and flank around to fire at the enemy's behinds. If you have another medium as a partner it works very well. I find that the Panther is a good partner; you have a strong alpha gun and the Panther has a strong penetration gun. Flanking effectively can net you lots of damage and kills.
Another technique is to do peek-a-boom. T-43's acceleration is pretty good so you can poke out, fire, and retreat before the enemy has a chance. In this style the gun can be inadequate because shooting frontally, your gun might not be able to penetrate, which is why this tank is better at flanking. But engaging as a front-line support is still plausible and is a technique that I tried occasionally.
Have fun with the tank.