No slippage for limit order in ECN?

I personally haven't used any ECN before. Logically speaking, your limit order must be taken up first since it is a better price, unless someone put another order inside the spread. In that case, your limit order is partially filled, with the remaining waiting to be filled given that no one put another order inside the spread.

Just to confirm the veracity of this statement: there's no slippage for limit order in ECN, regardless of order size?

Slippage has always been associated with bad things brokers do to your position.

However Limit Orders do have slippage as well. But on ECN, the slippage on Limit orders are good for the trader. ie, you are filled at better price.

example:
You have a Limit SELL. Obviously wanting to sell at a price higher than the current price. Let us say you want to SELL EURUSD @ 1.3220 when eurusd is currently at 1.3210. If eurusd suddently jumped from 1.3218 to 1.3222, you will be filled at 1.3222 and not at 1.3220.

See how ECN handles Limit Orders? You are filled at your price OR better.
Happens all the time.

But for Market Makers, they will fill you at your price or worse but NEVER BETTER.

Stop Orders are a different thing. ECN and Market makers will fill you at your price and/or worse than your price. That is how Stop Orders work.

There is always a possibility of slippage in any type of orders. With Limit type orders the slippage is always in your favour. The only thing to worry about is that your order wouldnt get filled completely.

Or that your order wouldn't get filled at all...

doubt any broker will give you slippage on a limit order as this will be in your favour (i.e positive slippage).

general rule of thumb on the desks i have been on is to slip on stop orders and just fill limits (no slippage)