Bitfinex is fine if you are planning on spending a lot of money, but they will not let you trade smaller amounts of money. I'm very happy with coinbase for bitcoin, but I wanted to dump my ethereum profits into Iota. I'm in the habit of putting small sums into a new application to make sure there are no problems. In this case, I dumped .08 Ether in only to discover that the minimum trade and, indeed that the minimum amount you can remove, is equivalent to $350 so they got 0.08 Ether out of me for nothing. Call me cynical, but I'm not putting $350 into anywhere that will allow me to deposit money they know I can't use or withdraw. Fool me once.
Here's what you see when you try to withdraw the money they allow you to deposit but don't let you use. I'd assume that this is a nice little earner for them:
https://s2.postimg.org/r2q55b5vd/bitfinix_ripoff.jpg
As a result I ended up using Binance as it was the only other reputable exchange that was trading ether to Iota. I'm very impressed, although their verification process can be a little slow so get all your ducks in order well in advance of jumping on any movement in the markets. I've also found Metamask useful for shunting small sums around and allowed me to be agile enough to make a decent and hilarious profit out of the first surge of cryptokitties. I'd really recommend having a fifty quid play with cryptokitties as it is, for want of a better word, the cartoon version of all this, or more accurately the bastard child of ether and pokemon. As with so many other cryptocurrencies, you'll enter close to the groundfloor, so after you get bored just make sure you don't lose the passwords as it could go ballistic once ethereum solve the scaling problem that cryptokitties has so cruelly exposed. Me, I'm breeding gerbil faced leopards and fancy duckcats:
https://s2.postimg.org/dn34g2009/104559.png
It's the daft end of bitcoin investing, but I'm about half a Rolex up and saving the rump to see what happens when ether starts to scale properly.