Kaisei 022 is double butted 4130. The main tubes have a wall thickness of .9/.6/.9 which was the "standard" thickness of high performance racing tubes for decades. The famed Columbus SL/SLX and Reynolds 531C were both .9/.6/.9 and both ride/rode wonderfully. If you are lighter than 140 pounds and/or ride a frame smaller than 54 cm. or so it is unnecessarily heavy for you and will give a stiff ride. If you are over about 190 pounds and/or ride a frame larger than 60cm or so, it may be too light for you and will be a bit whippy. (I am 200 pounds and ride a 63, but enjoy a flexible frame so use this wall thickness.) The fact that it is seamed is unimportant. Some of the best tubing in the world is seamed. Done correctly, the seam is undetectable inside or out and does not weaken the tubing at all.
I do not know the specifications of Tange Infinity, but have seen it spec'd in some lower end frames, so suspect it is lower quality than the Kaisei.
HTH!