Whomever you achieve the most satisfaction out of playing at whatever level you prefer to play at. And there's nothing wrong with having secondaries, so there's a chance you could still find a use for both. E.g. characters who can exploit Cloud's more exploitable recovery, you could opt for Roy's slightly less-bad recovery. Or characters that zone out Roy with projectiles, you have an anti-camp tool with both blade beam and limit charging on Cloud.
IMO Roy is the better character. He's strong and fast, and has less commitment on his attacks in comparison to Cloud. And then you could have Chrom who plays similarly as an easy backup if you're having any sourspot issues. But Cloud is still a monster onstage - it's just his recovery is awful without Limit.
