So I just got the Sun Sword after relying solely on the Longsword through almost the entire game. There doesn't seem to be much difference between the swords, other than the Sun Sword getting a bigger bonus out of my STR and DEX (which I'm assuming the A B C D letters at the bottom determines)
My Longsword is at +10 now, and my STR and DEX is at 60. According to my genius math skills, the Sun Sword should be doing a bit more damage once it reaches 10+ (366 vs 380)
So my question is, is there any downsides to the Sun Sword I'm missing? Any other reason I should stick with my Longsword?