Does age have any bearing on your first impression of an incoming soldier or NCO?

Ambition wins the day!  Age is part of your first impression.  I've had both sides of the coin reporting as a 27 y/o 10yrs TIS SFC and continuing to prove you've earned your spot and then being the 30 y/o 2LT where age and prior service gives you a long leash.  Keep ambitious goals and don't worry about the whispers...What's the quote of the week, "A lion doesn't concern himself with the opinions of a sheep."

Age, no...However I do believe the Navy has a flawed advancement system in which the Sailor takes a test for advancement. So in theory, (and I have seen this in a couple instances) someone could in fact become an E-6 in their first four/five years in the Navy if they are a good test taker and have a great memory and study habits. Thats great for them; good job; but unless they were a supervisor as an E-5, how are they going to be able to lead a division as an E-6? They have had very little "people-management" time in order to learn how to be a leader

It comes down to certainly time and what you have done to achieve your rank.  Most people including myself cannot speak intelligently on this topic because no one really knows a specific or realistic time frame when a Soldier should be promoted after earning E-5.  I would say this, if you have the knowledge of Leadership and understanding and compassion for Soldiers genuinely.  Then it does not matter what, why, or when you were promoted.  Jealousy is the biggest form of flattery.  Congrats on your E-6;  I would suggest to tread with caution however; look at the trends currently evolving rapid promoted NCO's are going to begin to possibly get removed from service,  You cannot hold a E-7 slot up for 10yrs because you don't meet the time requirements for E-8.  What I mean by that is I had a nice immersion in my career check my profile out.  I was E-5 in five years, on my ninth year I was promotable, and my 11th year I made points.  The Army is saturated with NCO's; the leaders who will survive the cuts and uncertainty will be those that have well-rounded knowledge, deployments, and a desire to train mold and develop future NCO's.  I don't want to take away anything from you but rapidly promoted NCO's have caused problems amongst the slower more steadfast NCO's If you were promoted so quickly did you learn enough writing 4856's to now rate an individual.  Maybe this is what your command is thinking of you.. How can a E-6 with five/six years in possibly attain the skills to evaluate his own subordinate NCO's properly...when you had little to no time EOM, Corrective action, and positive action 4856's to E-4 and below...???  Think about it,,, it can go both ways...I have seen it.

battle keep moving forward soon you be the boss

Not really int erms of a negative first impression but when an older individual comes into a unit, and by that I mean, an age where they're noticeably older than their peers, it gets me curious as to why.  Did they enter late?  Did they get out and come back in?  Is there something wrong that's made them get overlooked for promotion?
On the opposite side of the age spectrum, I've never really given it much thought on someone who's young coming in. 

People believe with age come experience but their are also people out there who have experience more because they have lived there life's.  If A troop or a NCO is profession, can PT and know his/her job then growth is there.