Do you have to sit for minutes to replenish your power or hp ,  or does it actually go up fast with no real downtime (think Warhammer)

It's fine, you do have to sit for maybe up to a minute or 2 at most for hp, mana i'm not sure about. If you feel its to slow you can always use odella powder/food to speed things up.

Depent,
Just buy some potion and Herb tretement and you will never need to sit :)

It depends on your class, the mobs your fighting, the skill rotation your using, your gear quality, and your willingness to use consumables(consumables are cheap).

My assassin can grind non-stop if I use herbs and/or pots.  And I usually can kill 4-5 mobs before I becomes necessary for me to stop otherwise. This can change drastically depending on the type of mob I'm fighting... for instance "mage" type mobs with high damage spells and low health point totals are a prime choice for me, because I can evade/stun their spells and burst quickly through their health.  However I have a lot more trouble with tankish type mobs that require me to stand in front of them for long periods of time, or multiple mobs at the same time (because a sin can't lock down damage on both of them).

Going from low health to full health takes maybe 15-20 seconds if you just sit down and wait for it to restore. 

Yes, it depends on the class.

While my cleric had no downtime between the kills, to kill something took her quite a while.  So in a sense her "downtime" wasn't between the fights, but the fight itself slowed me down :)

I play a Cleric.  Most downtime I have had (level 24 atm) is like 1 minute at the most.  So basically: Whats downtime ?

Originally posted by wolken13

Depent,
Just buy some potion and Herb tretement and you will never need to sit :)

This!

There are money sinks all over the game and one of them is consubable items.

I rarely have downtime as a sorcerer because of things like mana treatment and potions.

For Warriors it seems bandages and potions are the cocktail of the day.

Pretty much zero downtime if you're willing to buy potions/food.

Some classes like priest will have next to zero downtime because their heal drains about no mana and their main attack is melee.

Some other classes like mage will have a killing spree before having to sit to restore their mana, taking no damage.

Warrior and scouts will mostly sit for hp. Scout kills fast and stis more. Warrior kills slow and sits less.

I've ascended every tier 1 classes but i can't really speak for every tier 2 classes. My main is an assassin. Basicly it doesn't rely on mana. It uses some but the costs are so trivial that even by spamming those skills that do require mana you'd be regening it as you go. An assassin relies on stuns to remain alive. If you play it badly or if your stuns get resisted you'll take more damage and you'll have to sit more.