In the Year 2525
My personal philosophy is that unless the extra title is a team up book (in the vein of such classics as Marvel-Team-Up, Two-In-One or DC's Brave and the Bold) that an additional title is almost always overkill. The reason I loved those titles is that it used popular characters that most fans liked (Spider-Man, Batman) and gave some face time for quality lesser known characters and concepts that usually wouldn't have been used in the character respective main titles.
"I was handed a chocolate bar and an M-1 rifle and told to go kill Hitler."--Jack "King" Kirby
I remember Marvel in the late sixties and seventies. Each character had one book. It was easy to follow their adventures, and when there was a cross-over with another title, it meant something (sort of like Daredevil is now). I like Wolverine, Hulk and many others, but trying to follow these characters through mega events, cross-overs and multiple titles has become a headache and just isn't as enjoyable as it should be.
Blah Blah Vision+Wanda=4Evah Blah Blah