I'm pretty sure I play quite a bit of f2p games, thanks for assuming. I was excited for DDO when it was announced, being someone who will take more DD in any form. Slightly less so now that I've played to level 20. I say slightly because I have blind love for the series and will play it nonetheless.
The nights aren't as dark aside (wtf capcom), boss fights take forever to clear solo, not because my weapons are shit but because there's this shitty rage mode that reduces damage taken to minimum. It takes forever to get rid of rage mode via stamina drain when soloing, so even when you take on a level 12 cyclops at level 17, it still takes quite a while to do it. The bulk of your time is spent hanging on to the cyclops to do "tugs", not shooting arrows. It's a lot less satisfying to fight giant enemies in DDO. I dread it instead of anticipate it like I did in DD.
They claim that you can play DDO solo but it isn't true. Not if you want to enjoy it. It's not something they can't fix by patches/balancing, but there is something missing from DDO's giant enemies still. I can't quite put my finger on it. Is it the body part farming? Hmm.
Everything is a very slow grind, with everything (quick travel and pawn rental, anyone) costing some sort of currency. This being a f2p game, nothing comes by that easily. There's even an equipment gacha if that's your thing. Silver tickets for gacha come with daily logins and the occasional events.
I expressed hate for f2p only because I've played it and think the f2p elements only detracts from it. Greatly.