I would take it in - just to rule out any issues with the wheel speed sensors (just in case they got damaged with all the work you've already done). If they check out OK - then it will be a matter of getting used to the new system.
A technician might be able to change the threshold on ABS activation - but more likely that you'll just have to just adapt to the sensitive brakes. Might consider upgrading the tires to something with a bit more bite (OEM Bridgestones - depending on market - are just an OK tire, little too slippery for my tastes).
Another part of the issue is many owners complaining that ABS threshold is too high - needs too much pedal pressure to engage. Used to be around 90lbs -125lbs of pedal force - not happening with some drivers.
Sometimes it is just a matter of getting used to the brakes - practicing emergency braking in an open parking lot or clear back-road and find out exactly where that activation threshold is - then back off the brakes a hair to get the best braking performance.
Each car is a little different - some require lots of pedal pressure, some very little. A Toyota Prius that I've test driven - I've never was able to come to a stop WITHOUT having the ABS kick in - even scared the sales guy a bit.
My own 2009 Matrix XRS - just breathing on the brakes will cause the ABS to engage. Compared to the previous 2003 Matrix XRS - you had to really stand on the brakes to get ABS to engage. Took a little while before I got completely used to the brake feel - but now I can properly threshold brake without ABS kicking in.
