[name_f]Do[/name_f] you think this name (with any of the spelling variations) will be the next [name_f]Sophia[/name_f]? We are considering it but I tend to shy away from super popular names. I think it would be a little bit frustrating if we used it and then in a couple years it’s in the top 10 or 20.
In my opinion, it is already as popular as [name_f]Sophia[/name_f] and will be more so soon! With all the spelling variations it is over the top-- not to mention all the [name_u]Madison[/name_u]'s which has a similar sound as well…
With that being said, if you love it then use it! But be prepared for the popularity!!
Booo 
A lot of the names that I have loved for 10+ years are really popular now, even though they weren’t at the time I fell in love with them. [name_f]Olivia[/name_f], [name_u]Evelyn[/name_u] and [name_f]Isla[/name_f] are examples and I love [name_f]Sophia[/name_f] too. I have a pretty uncommon name and I really liked that I never had anyone else in my classes with my name. There were always a ton of [name_f]Brittany[/name_f]/[name_u]Ashley[/name_u]/[name_f]Jessica[/name_f]/[name_f]Amanda[/name_f]'s (and all the other names that were popular in the late 80’s) etc out there.
Personally I see them as separate names;
[name_f]Madelyn[/name_f] - MAD-uh-lynn
[name_f]Madeline[/name_f] - MAD-uh-line
[name_f]Madeleine[/name_f] - MAD-lehn
But really you can look at them as a cluster of quite similar names (like the [name_u]Aidan[/name_u]/[name_u]Hayden[/name_u]/[name_m]Braden[/name_m] etc names) and altogether I think they’re on their way to becoming quite popular.
I would have to agree that the [name_f]Madeline[/name_f] group is already a solidly popular name. Off the top of my head I know 2 Madalyns, 1 [name_f]Madeline[/name_f], 1 [name_f]Madeleine[/name_f], and 2 Madelyns of varying ages and I could probably think of more if I took the time (Though some people pronounce all these differently, all of the ones I know pronounce it the same way: MAD-uh-lynn). According to the 2012 Name Nerds list (which does a “playground analysis” and ranks popularity by taking into account all the different spellings of one phonetic name), [name_f]Madeline[/name_f] and its variants rank at #15 for girls–pretty high in popularity.
That being said, [name_f]Madeline[/name_f] is a lovely name. I don’t particularly care for any of the -lyn ending ones, but I absolutely love [name_f]Madeline[/name_f] (especially when it’s pronounced with a long i) and [name_f]Madeleine[/name_f] (which just looks so pretty to me). It’s on my list despite its popularity because I love it so much.
But if you really don’t want a popular name, I wouldn’t use it. You could consider using the long-i pronunciation (very uncommon, at least where I live) or a variation like [name_f]Magdalene[/name_f]/[name_f]Magdalen[/name_f]/[name_f]Magdalena[/name_f].