NothingSafe:They're pretty solid. Although, they're not as good as they used to be. I miss the 'Herzeleid' days. Now they've become a parody of themselves. Songs like 'Engel', 'Rammstein', 'Stirb nicht vor mir' are infinite, though.
I don't think they got worse over time, sure Herzeleid and Sehnsucht were great, but the latter records simply show another side of them. I've met dozens of people who prefer Mutter or Reise,Reise and I guess its just up to the person.
They sed the new album will be much like Herzeleid...So that's good news for you 
Love, Hate, Love...