I mean, there are advantages that Roy has over Marth, and you can do pretty well with Roy in the competitive world (just not at the higher/highest levels of competition). It's really easy, especially when you don't have good people to play, to say to yourself that Roy really is a viable character and that the only reason he isn't used as Marth is because of his lack of a developed metagame.
There was a time (albeit brief and a long time ago) that I thought that Roy had loads of untapped potential and that he could become relevant in the current/future metagame. The reality of the situation is that once you really start to use Roy in tourneys you are going to have to deal with his weaknesses (which good players will exploit). I had a great time playing friendlies with a Samus player a few weeks ago trying to gain some knowledge about the matchup, but the longer we played, the more familiar he became with the matchup as well. He knew how to cut off my options with ccing and I found that taking a game was very difficult (I lost frequently).
The thing about the Samus player was that I did not feel he was at all above my level of play even though he repeatedly 1,2, or 3 stocked me and I won about 2 games of the maybe dozen that we played. Could I have won? Surely, but I would have to be a notably more skilled player to do so. I'm fairly confident I could have won the majority of the games with Marth.
I dedicate my time to Roy, I love the character and I highly respect the people that put effort into him, but even with about a year of Roy play down (limited I know) I still can outperform my Roy with the Marth I put about 4 days of work into (and never practice).
To all of you out there looking to improve Roy, that's great and I wish you the best. Nobody more than me wants to see our boy be relevant in competitive play, but just understand that you aren't the first to attempt to take his play to a higher level. There are fundamental flaws in this character that will limit you greatly.
What this guide needs is to be more than just a pro/con list. Roy has strengths: go in depth with his moveset and how to take advantage of his shffl. Go in depth with how to space all the various moves and what you can do off of a hit confirm (not much unless it's d-tilt or maybe dair). Talk about stage striking in various matchups (I live or die by Yoshi's). Talk about Roy's strong matchups (typically still disadvantageous but some aren't absolutely terrible). Teach people have to take advantage of Roy's movement and great grab range.
Even more important, talk about Roy's weaknesses. You will never have any success with a low tier if you solely play to the strengths of the character. Roy has issues with his character design that need to be acknowledged. Address the combo game (or lack thereof). Talk some about Roy's bad matchups (Pretty much everyone not trash tier). Explain how to deal with crouch cancel happy opponents.
It's great that there is info about how Roy differs from Marth (and in a few instances is better), but it means very little if there isn't any info on how to take advantage of his strengths and avoid his weaknesses. Above all, don't try to convince people that Roy is a viable alternative to Marth in competitive play: he is not played for good reason (many people have tried to at varying levels of success, but none have done so at the highest levels of play).
Also, putting flare blade 1HKO as a significant reason why Roy is as good as Marth really just goes to show how much worse he is.
