Not fun, nor rewarding.
I played this game for two years.
Two... years...
And what experiences did I leave with? Nothing. I can't remember a single 'fun experience', it was just a constant grind fest. Like a boring job, but instead of getting money, you get a +1 next to your Coal ore, or Fish, or Combat level. WHAT IS THE POINT IN THAT. I mean sure you could say the same thing about any other MMORPG, but at least you have fun while doing it! This is just a constant grind!
The only thing Runescape has done well, is that it can be played in a browser. I applaud them for that, I really do, it's quite an achievement and they pulled it off well. Now if only they made the actual game FUN TO PLAY, then I'd be happy.
The majority who play Runescape are usually people who think a monthly subscription fee to a quality MMO like WoW is "OMFG SO NOT KEWL AND EXPENSIVE", so therefore they are all preteens that don't have a job.
Seriously, do yourself a favour, and get a decent MMORPG like World of Warcraft, LOTRO, or EVE Online. Sure you'd be paying a bit per month but you get what you pay for.
Also, it's come to my attention that in one of the latest updates to Runescape, you cannot trade more than 300 gp (gold pieces / money) at once, on the Free servers. This makes me laugh. They're pretty much forcing you to buy the Member account, and so since you're paying real money for this joke of a game, you might as well get WoW.