Anyone here ever have problems with large lots on short term trades?

You know, problems like: broker problems, larger spreads, Stop losses not triggering, Stop losses triggering too much, not able to close position to make profit, slippage, etc...

I'm specifically wondering if these things or things like this occur when trading short term with larger lot size's (5+lots), especially for a sucessful short term investor

Thanks in advance

No, if there's any problem, it's always my own problem which incur losses.

Im intraday trader, i trade regularly positions bigger than 5 lots. You should be very patient with choosing right broker! (find which liquidity providers that broker have)
my experiences:
- positions around 50 lots are not problem, execution until 0.5 sec + expect wider spread around 0.5 pips more than in case 5 lots (during standard times - London, NYC sesion withou news time)
- during news time is more difficult to open and close such positions very fastly, every execution take more time plus cost much more money to close thanks to bigger spread
- for opening positions i use market order, but for closing i mostly use limit order to reduce costs

first of all I don't know what a lot is for you. Do you mean 1 million units, 100.000 units or 10.000 units?

Secondly, this all depends if you are in a fast market or not.

Dukascopy traders place 200 million on eurusd without any problem, FXCM, up to 50 million per click goes easily

Any retail broker that do not allow up to 10 million per click (thats 100 standard lots), except mt4 platform, forget them