I tried my GTS today, only to remember that my version of Platinum does not show levels, making it a guessing game at them D:
However, when I still had a lot of stuff on Pearl and used the GTS, even back 2 years ago, people didn't have much common sense. I do not feel like trading a LV 100 Elekid for your LV 5 Turtwig, good sir! Legendaries will always be the worst though. Phione for Mew, LV 50 Palkia for LV 100 Palkia, and anything for a Level 9 and under Mew is just silliness manifested into a video game. Overall, while the entire idea of a GTS is good, the execution kinda got messed up by people's silly demands.