Rome had a pretty high amount of sex and violence by the standards of 2005. But the envelope has been pushed much further since, and one of the series to do so was Spartacus.
Having said that, I think Rome was a pretty good series. Far from flawless, and certainly not a masterpiece, but it was enjoyable and engaging. It did a reasonably good job of dramatising history without doing any infuriating mistakes. For the most part, the sex and violence scenes had a purpose, either in terms of plot or in terms of characterisation. It was decently written and had some characters that I genuinely cared about, and it was also, for the most part, well-acted. It's biggest flaw was that it was too ambitious, and the writers had something much bigger in mind, as many of the subplots indicate. It could have been great had it been granted more than two seasons. But in general, behind the boobs and the blood-dripping daggers that dominate the series' general perception, there was actual substance to it.
I've only watched two or three episodes of Spartacus, so I may not be entirely fair in my assessment. But those episodes completely turned me off. It was horridly acted, it had blood for the sake of blood and tits for the sake of tits, and whatever shimmered through inbetween was intellectually appalling. The dialogue was corny, stupid and empty. It was dumb and cheesy and just made me angry. I didn't even bother to check on the historical accuracy, but judging from the two lines of actual dialogue and my admittedly limited background knowledge on the Spartacus revolt, they were pretty liberal with history.