I second that. Silo has the features it needs, nothing more. It's extremely efficient, highly configurable and light on ressources. You will need some time to reach it's limits, and when you reach them, you could start learning ZBrush. But that's a fully different beast, don't worry about that yet. 

When it comes to rendering, you should really think about what you want to do. If you want to create stuff for Poser or Studio, you won't need a full suit like Modo. Modo's renderer may be superior to Firefly (from all what 've seen, it is), but that won't help you unless you want to make it your main platform - then you would create stuff for Modo, not for Poser.

Silo's normal working preview is enough for me for modeling. If you want to render your model, you most probably want it to look good, and that means that you should work with the lights, the scene, the render settings. You need to learn your rendering engine too, and that's a thing you have to do over and over again, for each renderer. I can get what I want from Poser's Firefly usually, I need much more time when I use Vue as my rendering engine. Not because Vue is worse, just because I know Poser better. 

A ship in port is safe; but that is not what ships are built for.
Sail out to sea and do new things.
-"Amazing Grace" Hopper

Avatar image of me done by Chidori.