Should Mass Effect 3 be played with From Ashes or not?

Solution 1:

You should complete the DLC as soon as you can after Priority:Mars.

You get a squad member Javik. But he will only be available after Priority:Mars.

IMO he is a very valuable squad member with very unique dialog options. I was able to do it fairly early in the game. His Dark Channel works wonders for me.

Adding Javik to your squad does net you some unique dialogue options when interacting with characters. (Not posting it here. But checkout Javik/Unique Dialog here.)

If Javik and Liara are on the mission Priority:Thessia, then that conversation adds a lot of lore, since at that point you are at a Prothean place where they posted a record of their attempt to fight the Reapers, as the Asari call it a temple and Javik is a Prothean.

One last note, you can not take him on Priority:Palaven.

Solution 2:

Having played the game through both with and without the 'From Ashes' DLC activated, personally I didn't find that the presence of the additional squad member made the game any different.

There are various instances throughout the game where he contributes lore and discussion, occasionally shows a sense of humour, but there are no changes that are really beyond superficiality.

However, the following is worth baring in mind;

• The quest line added to the game by From Ashes DLC allows you to find a weapon with your new squad mate, which is decently powered if you complete the quest line as soon as it is available to you, in comparison to the weapons dropping at that point in the game.
• Completing the quest line mentioned in point 1, will net you 25 war assets, which will aid you in getting a higher EMS rating before entering the final mission.