I have another character around lvl 50 where I've alternated as a mage and fighter. The other day, I created a ranger and it's surprisingly fun.
Not even lvl 20 yet, but it's great to be fast, have high dps, not having to wait for mana to recharge to do ranged damage, and not to having to hunt down annoying little fodder. Soloing is a little tougher than mage, but that's largely due to my squishiness after putting all of my points into agi. Rangers really shine imho in a group, esp. with a fighter or 2 to take the pounding for you. Being able to knock out healers/archers/whiskers quickly and at a distance makes dungeon crawling so much more tolerable. Haven't fought a lot of bosses yet, but again, I imagine that boss farming with a party is probably the easiest way to go.

The crit ranger build with all the points into agi/speed and + crit bonuses seems to work very well.

I haven't tried PvP with any classes yet, but I'm especially curious to hear anyones experiences PvP'ing with this class.

Well I am qutie some time a ranger now. Before this patch they are considered by me as the best class, possible to reach upto 15k dps, Now I can crit 1 shot out of 5, and my damage is around 1500-3200 what was used to be 2k - 4k before patch. Hard thing is that crits will become usefulla t high levels as low level gear got low crit chance.
Formula maybe nice: 3 * (crit/100) + 3 = % of actual crit chance.

As for pvp, the critical ranger is still good but its better to wear a split or 3/4 end gear, as you'll need it, poison shot is usefull also. Mind that you need to get a good speed with good damage, only hard thing is that you'll be running on TTF, and when you die once its useless for 220 sec. So better have a good speed already