If done correctly they are equally the same. Welding 4130 is difficult but not impossible. In ww2 they only used oxy/acetylene to weld the aircraft. They used a mild steel rod and the oxy/acetylene added the needed carbon lost with the low tinsel strength rod. Also the heat was sufficient to heat treat the 4130. Now days tig is the way to go but many precautions should be taken. You need to purge the inside of the tube with argon to protect the root of the weld. If you use 4130 filler you need to heat treat the weld asap with an oxy/acetylene torch. depending on the thickness of the metal you may need to preheat before welding. You can also use a high tinsel wire like an E70. There are a lot of bad things that can happen if done incorrectly with both processes. Good luck!