There are tons of new quests, player abilities, new areas to explore and new pvming supervisors. Btw yes RS3 is much more of cheap OSRS Gold a pvm game than pvp. Since no one wants to hazard items that took them 15 hours to get from a boss so regrettably pvp in this game is dead. If pvp articles or nostalgia is I would recommend OSRS. If however, you're open to the new changes in this game or if u fancy lore, updated/modernized gameplay vs the notorious old runescape ability beats then RS3 is Runescape for you to stay.
If you like the PVP and the sense of the 2007 style Runescape system, I'd say go with OSRS. If PVM and quests are important for you and you enjoy the EOC system, I would say RS3 may be the better option for you. You can swap into the heritage program in RS3. I swap when I get bored of play and RS3 OSRS and then when that gets boring, I keep playing RS3. People who argue to be superior are delusional. They simply waste time arguing, but in the close of the day, everyone always will have their own preferences and opinions. Don't get sucked into it and play any version of Runescape, so that you can decide for your self, which variant you prefer.
The upsidedown, is RS3 has much more going for it as far as endgame goes, and the road getting there is much smoother compared to old school rs. Microtransactions have entered Runescape in this manner that trivializes training annoying skills, as you can just essentially purchase your way. If microtransactions get your platelegs / skirt in a spin, you could always play Ironman mode where there's no option for purchasing your way into a 99, but you also can't exchange players. Overall the reason I do not play with school, is because I have sunk almost 10,000 hours in this match already. I really don't feel like doing this again just for the nostalgia.
Take a look at 2007 Runescape - your own accounts advancement will still be on runescape 3 though, you can play a version from back in the day (using a lot of additional updates by today, however same core gamplay and graphics) everyone left a fresh start on 2007scape servers. This would be the runescape how you remember it, if you're looking for participating pve content I would totally have a look at RS3.
The Chosen Commander is the best quest in RuneScape
I had the honor of re-playing some quests within DXP weekend mostly for better agility training, and that I chose to perform the Throne Room for a while I remember it being one of my favorite Agility training areas believe it or not. I had to do the pursuit. I understood I hadn't. Since it would be the start of the end to the storyline that made me fall in love with RuneScape, to buy RS gold start out with. I've a bizarre attachment clearly, Zanik is my favorite character which says a lot since Guthix is a total Boss dude, and I would still roll with Zanik prior to him. I had started some of the quests, but it was The Chosen Commander pursuit that made me cry like it did years ago.