The Freitek-SoroSuub T-53 was designed on commission for the New Republic, as Rogue Squadron's performance during the Battle of Hoth and the effectiveness of the T-47 in a light ground attack capacity demonstrated the value of a dedicated low altitude attack speeder.
The T-53 was manoeuvrable, well-armoured and armed to the teeth, allowing it to provide formidable cover for ground troops and making it well-suited for planetary invasions. Like the Slayn & Korpil V-wing, it was deployed from transports at high altitude and able to coast down to battlefields alongside infantry dropships. Alongside the speeder's pilot, a gunner/radio operator sat lower and further forward in the nose, managing the speeder's ordinance payload, controlling the two dual blaster turrets and maintaining contact with ground forces. The T-53 was intended to take on any threat, and had the flexibility to provide infantry suppression, air superiority and armour-busting.
The T-53 was a competent vehicle loved by ground forces, but fell out of favour depressingly quickly after its roll-out. For one thing, it was difficult and expensive to maintain, making it unsuited to garrison duty on worlds without serious manufacturing capabilities, and was well-known as an attention-hogger for ground crews. In addition, it was intended to take the pressure off the New Republic's Starfighter Corps for ground assault, but this need became less of an issue as the Republic established itself and competent strike fighters like the X-wing became more and more available. Indeed, the X-wing was substantially easier to fly than the T-53, which required skilled handling and specialised training that was hard to come by on backwater planets, whereas any teenager with more than two braincells and a skyhopper could learn to fly an X-wing.
(Renders available above, and also here at
https://imgur.com/a/sYHAuxd )