I play it from time to time, I played RS long before 2007scape and I can tell you it is not OSRS, Moparscape does better. However I have a lot of family and friends who are still heavily invested in RS, mostly OSRS. I find OSRS too easy, my brother made a new account 2 months ago and has every skill at 80+, I made a new account a day after him and was gaining levels and gold faster than he was, but for me it has always been a nostalgia thing, going back to a game from time to time for over 15 years.
If you guys ever want to see the game that inspired RS Classic , google up Tibia and give it a try, will blow your mind when you realize the age of these games and their basis in MUDs.