In all fairness everytime I call realtick they answer the phone and are helpful.
I used Datek and the cost for the "software" is free. Now I am paying $250 a month. I also use Quote.com and Stock watch Pro for screening.
To answer your question.
1. I don't like how often (at least for me) some of the level II gets messed up. I know that they claim its the ECNs fault and maybe it is but every time it appears to be working fine for quote.com
2. I dont like how my balance needs to be multiplied by 4 to give the true balance.
3. I dont like the charting
4. I dont like that I cant trust putting in an order at home and then going to work and changing the order.
5. I don't like that all the features seem to be ARCA related and I trade on Island ( post for the rebate)
6. I don't like having to cut off my post at a penny instead of shaving off a little. i.e. ask price of 25.199 instead of 25.20
7. I don't like the times I lost money due to not being able to close out a posistion or conditional order due to the damm thing screwing up
Mostly I just dont like paying for an order entry program. While that is my brokers doing it does not mean that I have to like it.
I did like the rapid entry with datek and got good at it. Perhaps in time I will get good at realtick or even more likely flip over to something else. also I should state that I have only used realtick for about a month. Maybe I just have not given it a full chance????