You aren't the only one, I have the following:
3x Fatebringer - 3x max
3x Visions of Confluence - 3x max
3x Corrective Measure - 3x max
3x Vex Mythoclast - 2x max last is maybe 2 bubs
3x Icebreaker - 2x max (plus 2 were max then upgraded, and maxed again) and the 3rd has both perks unlocked 2 bubs from max)
3x Suros Regime - (2x were 300 maxed, then upgraded and maxed again, last one is about 3 bubs from max)
3x Atheon Epilogue - 3x max
3x Black Hammer - 3x exp maxed, only 1 fully maxed, and the others I'm waiting until I get my titan 32 before spending more energy, but I have lots
3x Murmur - 3x maxed
2x Gjallarhorn (would be 3 if I could) - 2x maxed (1 was max 300, upgraded and maxed again in 1 day)
2x Thunderlord (again, would be 3 if I could) - 1 was max 300, upgraded and now 2x 3 bubs from max
2x Patience and Time (was 4x but who the hell needs 4... or even 2, I never use the dang thing) only 1 has both perks unlocked and 3 bubs from max
2x Hawkmoon - 2x 300 max then upgraded and both are 3 bubs from max again
2x Thorn (used to be 3... might still be I lost track) 2x 300 maxed, upgraded 2x and only just barely have both specials maxed on the 2x upgraded
2x Pocket Infinity (used to be 3... but just too many exotics to use) 2x max 300 then upgraded and 1x max now
2x Bad JuJu (had never really used before, but really starting to like it) 2x upgraded and now both are 2 bubs from max I think
I have quite a few other duplicates, but those are probably the most notable ones, I hate having to back out to the tower and swap stuff around, was really happy when I finally got my 3rd Icebreaker from the first Crota chest last week.