I have a quality mechanical keyboard that has Cherry MX Blues, but I wouldn't say that they are "extremely" loud. Each click is about the same as the sound of a nice retractable pen, only a little quieter. Yes, more sound is produced when typing, but I honestly feel that it's just "audible", not "extremely loud". Although, I know that no two people hear things the same way.
Also, the Cherry MX Blacks are said to be the best switch for gaming. If they were a "tiring" switch from being too heavy, then I think that no one would like them, especially for gaming. Of course for typing only, they might have a bit too much resistance. Although, some people love the Blacks for typing.
Really though, coming from the Lycosa, you will be extremely happy with almost any quality mechanical keyboard. If I had to choose between the Leopold and the Rosewill, then I would choose the Leopold because I had someone tell me that it's noticeably a little better than the keyboard that the Rosewill is based on (the same board mine is based on).
Although, I think that comparing these two keyboards is a little bit like splitting hairs.