Short answer is, I would choose Tren any day. Deca doesnt seem to do very much for me, I'm currently on NPP for the first time and only a week in so we'll see what happens with the shorter ester of nandrolone. Having bad digestive issue's hoping it will shake off so I can see what the compound can do. But my experience from Deca durobolin, I don't really put on too much size from it, I actually stay relatively lean which is funny as most people blow up on it. I do notice my joins get very comfy when working out though. Other then that the compound isnt really that great for me in terms of size.
Deca
Pros:
Joint lubrication
Faster recovery from workouts
Slow muscle gains
Nice pumps
Cons:
Sleep alot more
occasional lethargy
On and off sexual dysfunction (Not severe for me though)
Some Diarrhea (I know its odd but for some reason I get on and off diarrhea and I notice it only happens when I take nandrolone, its happening right now with the NPP I'm taking, or atleast I think its the NPP)
Occasional appetite suppression
Tren A (I only use Ace)
Pros:
Faster recovery
Increased appetite
Incredible pumps
Rapid increase in muscle mass
Ton's of energy, even with little to no sleep
Drastic increase in strength and aggression
Sense of wellbeing or overall confidence boost (Can't explain it but I feel incredible off it, like nothing can stop me)
Cons:
Random anxiety attacks especially at night (increase in heart rate)
Insomnia mostly from the anxiety
Occasional overflow of aggression that can lead to snapping at someone if they anger you.
Slight decrease in cardio
Some acne issues. (When I run tren for long periods of time, they get real bad when I stop tren for some reason)
Extreme appetite increase that can be an issue when cutting
The con's of tren A arent consistant and for me have been manageable. For me the benefits of tren outway the cons. That being said I would not run tren for longer then 8 weeks. I personally have only ran it for 6 weeks at
moderate to high doses. And have always had incredible gains from it. Gains wise I have never been let down by Tren. Without a doubt Tren is my favorite compound. It's a love hate type of relationship
To be honest judging by my npp cycle so far, I might never run Nandrolone ever again. I'll probably stick to Test, Mast, Tren and primo (when I can afford it).
Hope this helped.