Choosing best mobile performance solutions

I have question about mobile performance. There are several things, that are negatively affecting performance, but I can´t find any info about how bad they are. There are some situations when you have to pick one solution, but I really can´t decide which solution is better, because I dont know how much bad they are. For example: I´m making tower defense game and I´m making bullets for my towers. There is several solutions how can I make this bullets. First one is just make projectile (lets say low poly sphere thats have around 80 verts, some basic color and no shader). Or you can create plane, that have only 4 vertes, but you have to put texture on it and apply additive shader which will make texture transparent (like in this official Unity tutorial). How to chose between this two solutions? Is there any resources where can I find info about what techniques are most expensive in terms of performance? PS: Sorry for my terrible english

Either solution will work, difference in performance is probably so negligible that you wouldn’t even notice a difference. I’d say go with the quad solution, this way you can texture it and change the graphic at any time. Choose the method that fits your needs, I argue for quad, because you can customize it.

Taking a step further, have you thought about object pooling? Or do you plan on instantiating a bullet every time one is fired. This decision will affect performance more so than what is being asked in your question.