Benetau is a fine boat with good and bad points as is any other boat. there are many Catalina 42's that have circumnavigated so they would not be the first.
I am a fan of Catalina great boat as is Benetau,Jenau,Morgan and many others I would not say that Hunter is bad just not my cup of tea. having sailed all of these boats I can't say that I fint a problem with the 42 MKII I would take it in blue water with some modifications (more fuel and so on). But if one is serious about blue water you might want to look into something more in the line of Island Packet or pacific seacraft, there are plenty true blue water boats made with this in mind. Choose what works for you and understand that comfort at dock and comfort at sea are two diferent things and saftey comes first. I would look at as many boats as I could learn exactly where I plan to cross what is my experiance and budget are. Don't choose a boat from what anyone says (me included) it is just an opinion see what other people are actualy circumnavigating in knowledge in this case is your best friend!
I have sailed Benetau, Jenau, Hunter, Irwin, Catalina, Santana, Morgan, Cal, Newport, C&C, Tartan just to name a few and all are good for what they were made for some better than other some just ok. I realy like the I.P's and Tartans as well as Dephi these are some good over built boats.
what you realy want to look at is constuction and hull design, Keel type, rigging how much fuel does she carry? this is real important you will need it in bad weather and in duldrums. How much you are willing to spend on setting it up for offshore all this is important for a good safe cruise.
happy hunting and best wishes.