They are not the same. The 3/8 has 35ft lbs of tq, while the 1/4 only have 30ft lbs of tq. I chose the 3/8 due to having more sockets of that size than the 1/4. Also, i use 3/8 sockets more often than the 1/4. If i ever need to use 1/4, ill just use an adaptor.
Check out my review on it: