Maybe I'm being extremely picky, but I find it somewhat irritating when some people write down Japanese names in English and don't keep the order of first name and last name consistent. I found two such examples today, but I'm just going to post one: Arata Kagami (Sato Yuuki). How hard could it be to write these two names in the same order? Either write 'Kagami Arata (Sato Yuuki)' or 'Arata Kagami (Yuuki Sato)', although I must say I prefer the latter.
I watched Kamen Rider Den-O first episode and felt pretty much indifferent to it. I don't dislike the main character, Ryotaro Nogami, but don't really love him either. Most people who've seen Den-O seem to either like or dislike Ryotaro, and tend to judge his actor accordingly. It is too early in the series for me to form a solid opinion on Takeru Sato's acting ability, however. And for the most part, saying someone is a good or bad actor is pretty much subjective anyway.
Last, on the subject of Ryotaro's name, I've seen his name spelled as 'Ryoutarou' sometimes. I write 'Ryotaro' because that's the spelling they seem to go with on the official site. I've also seen this inconsistency with other names like 'Tendou' and basically any name with 'ou' in it.