I love both games.
But, as is often the case, now that I've played RDR2, I doubt I could go back to RDR1. The polish of the world etc in RDR2 would probably leave RDR1 in it's wake.
I totally get the criticism leveled at RDR2 (too easy, missions aren't exciting, controls are imprecise), but I honestly don't really care about all that shit. The missions aren't exactly taxing, but I don't care. I don't play it for an adrenaline rush or a challenge, I play it because it's relaxing and engrossing. My favourite thing to do in the game is just roam around, hunting and exploring, marveling at the world that's been created. I do some missions for a while, advance the story, then go out and explore. Try and hunt down some legendary animals, or just explore the world to see what I can see. Plus it's fucking gorgeous, which certainly helps. Easily one of the best looking games I've ever played (if only I could get it on PC for a decent framerate).
I also love the little interactions with NPC's etc around the world. Just yesterday I was roaming around and stumbled upon a house. Front door was blocked off, but a window was open up stairs. I climbed in and found a fucking horror show. Some freak has stitched together various animal parts, trying to make a mutant. Shit was genuinely unnerving because it came completely out of left field. I assume it's for some side mission that I haven't discovered yet. But I LOVE stuff like that. Just intriguing, bizarre stuff that you discover by yourself in the world. A short while later, I found another empty house. Went in to the basement and there was a dead body... or I thought it was. Turned out he was sleeping and there was another guy asleep under the table. Both woke up and started shooting. Had a gun fight, murdered them. Then there was a witness, so I gave chase. Finally caught him, roped him up and threatened him. He promised he wouldn't tell, so I let him go. Went back to the house and saw there was a big pile of money on the table, so I took it, then carried on my merry way. I'll never get enough of interactions like that. I just love it.
Again, I get the criticisms. But if you're after a relaxing game that centers on exploration and character, you could do a lot worse than RDR2, IMO.