Ferric Chloride or Ammounium Persulphate?

[AzzR]

Im am looking to start etching my own boards using PnP and sharpies etc but im wondering which is the better etching solution to use. Ive also found this thing called Riston which uses UV light but that looks to complicated making all the negatives etc so ill stick with whatever is the better etcher to use.

So which is the better etchant to use?

And what are the pros and cons of each?

Thanks

Dream

[powerplayj]

I've found that Ferric Chloride does better when you have to touch up traces with a Sharpie. 

[Paul Perry (Frostwave)]

I prefer persulphate. Less opaque, less tendency to stain everything, less fumes. And less poisonous (STILL POISON THOUGH!!). If you spill etch on yourself (VERY BAD idea) you will wish it was persulphate.
Downside: needs to be warm to etch.