Yes. The Stridsvagn 103 came before the K1 or even the K2. I knew that. The Koreans had hydropeumatic suspension first in 1988 with the K1 tank. I had not known that the Type 74 and newer Japanese tanks also had hydropeumatic suspension. The Swedes, Japanese and the Koreans all have this type of suspension to utilize the same principles of using the terrain to help improve their tanks chances of survival.
Regarding the size of the gun, yes the longer gun can be a determent to urban combat, but South Korea is keeping its K1 and K1A1 tanks so those particular tanks can be used if urban fighting is necessary. I also believe the K2 puts its gun a little further into the turret so it doesn’t stick out as far as it could. The Koreans believed that the muzzle velocity improvements out weighted the disadvantages of having a longer gun.
Yes, it is expensive, but a bulk of the development costs have already been paid for by Turkey as they have bought the technology (sans engine technology). This tank, if it ever gets sold at all, will have to be to countries that cannot buy a German or American alternative and Russia tanks are not an option for whatever reason. I also think this tank has a low likelihood of getting exported.
South Korea, like Japan, has decided to move main battle tank technology to domestic companies and that has a longer R&D arch as well as higher associated costs. Independence has its price.
The 0–32 km/hr acceleration in 8.7 seconds is disappointing since tanks like the M1 and Leopard 2 can achieve the same speed in about 7 seconds. The newer M1s and Leopard 2s are also heavier but can still accelerate faster. Korean heavy duty military grade diesel engine technology still has a ways to go.
I don’t think the Type 10 is a good tank as a comparison. It’s a fine tank, but it’s quite light for a main battle tank at 45 tons. The frontal armor might be good, but I don’t imagine its armor is strong beyond that. I understand the Japanese have made that compromise because they want the Type 10 to be able to operate on most Japanese roads and bridges, which have not been designed to support heavy main battle tanks.