To Stevia or not to Stevia.....

....that is the question.
There's been a lot of buzz about Stevia in the last few years and it's started appearing in some of our food and drink.

But how do you rate it?
 I'll be honest I tried Truvia when it first came out, hoping that it would be a pure stevia extract I could use; sadly not as it has Erythritol in it which is a sweetener.
So instead I opted for the pure Stevia powder; you can pick it up on amazon for a few pounds.
I was thrilled when the packet first came but a little put out when I opened it. Natural Stevia, unbeknownst to me, is like a green powder substance, reminiscent of the henna powder I used to dye my hair red in my teens. It doesn't smell too great either, a bit like a cross between weeds and black tea, yack!!
According to all the blurb Stevia is supposed to be 300 times sweeter than sugar, which I suppose is fine in theory but in my experience it really depends on how you use it.
I've tried several recipes replacing sugar with Stevia and they've all  been a bit hit and miss.

Finding a conversion chart for it doesn't seem to help either.In fact I've struggled to find one that works.
So far my I've tried a straight swap, stevia for sugar, and I've had limited success. If I add just a teaspoon-it is supposed to be 300 hundred times sweeter!- I didn't get any flavour at all. If I added a dessert spoon I got sweetness with an after taste of compost ( not that I'm in the habit of eating compost but I think you get what I mean). I've tried all variations in between but with limited success.
I'm not quite on the verge of giving up but I've popped it back in the cupboard for now before frustration sets in.
I'd love to hear from anyone who's used Stevia successfully or even if you've used it and suffered the same fate as me. Maybe you've found a conversion chart that's bang on and you're flying the Stevia flag. Hopefully you can shed some light on the rest us!