It's fine to enjoy both, I do have 4 installed still. Mainly to build things and create sims with. But actually playing the game is no fun to me because there's no personality. It's a life simulator that fails to simulate life. The shell is beautiful, but empty.
Sims 3 certainly has it's flaws. Which is why I mainly would expect a sequel to correct it. They did to some extent, but it's like fixing up an old car but taking the motor out. Sure it looks pretty on the drive way, but you can't go for a ride with it.
They have yet to make a sims game that captures what made every previous installment popular. With every installment they toss out too many things. I don't mean stuff that will return in expansions, but things that truly are at the core of the game that expansions can't fix.
