Marumi filters are not as famous as the major leading brand of filters like B+W or Hoya(Kenko) outside Japan. Might be due to the fact that they are not easily available commercially but domestically in Japan, they are pretty popular and easily available.
I have been using Marumi DHG Super filters for a while now and I can say I really like them. They are really well made (in Japan), keeps the water out, easy to clean and are really thin (about 2mm for the Protectors).
Have not use other brand of filters so can't provide you with any comparisions. The DHG series range from 2000 yen to 5000 yen (depending on size) for simple protectors and the Circular P.L.D will cost a lot more.
This website apparently have some tests with pictures of various filters so you might want to check them out. Click Here