Not really, at least according to the specs between RG-214 and LMR-400. If I was a HAM dude running HF through the cable than yes, I would probably be better off with the RG-214. Since, I'm pumping UHF freqs through the LMR-400, the LMR-400 has less attenuation with 2 meter freqs and above over the RG-214.You should loose the LMR400 and replace with something else. Even RG-214 would be a better choice.
I think I'll stay with the LMR-400.