Igualmente means the feeling is mutual not neutral. To expound a bit more, "igualmente" means "equally." So, if someone says to you, "Good to meet you," you could respond with "Equally," which means, "It's equally good to meet you."
I believe 'igualmente' is used more<u> when you meet someone for the first time </u>and they say to you 'mucho gusto' - meaning pleased to meet you - and you answer 'igualmente' - meaning pleased to meet you too. I would not use it for greetings. Yes, it's a bit "short" and could be considered rude.
