I just got my SS hooked up and running today. 
I must say, this thing is awesome! I'm running an old Dell dimension 3000 with 2.8mhz processor. I never could run Mach at more than 35k kernel at 1800mm/min velocity. I could jog fine at those speeds, but couldn't cut an actual part without the motors skipping, stuttering and generally be fussy.
I cut my first piece today at 3000mm/min without a hiccup.
I'll post a video tomorrow.
I am having just a couple of quirky issues though.
When I run my toolprobing script, it moves at an unbelievably SLOW pace. 90mm/min. My probe is located on the opposite side of my table from the home switches and it takes forever to get over there and down on the probe.
Also noticed sometimes my rotary table wont back off the switch when I home it.
Any ideas? 

Here is a vid of my mill in action with SS and Mach
http://www.youtube.com/watch?v=JaAjhnhsPfw

Without seeing your probing script I don't think anyone will be able to help you. For you limit switch issue you may need to adjust the filtering in the SS config.

Thanks for the reply Jeff. Here is my probing script.

Sub Main()
'probe
HomSigX = IsActive(2)
HomSigY = IsActive(5)
HomSigZ = IsActive(
Xreferd = GetLED(7)
Yreferd = GetLED(
Zreferd = GetLED(9)

If HomSigX Or HomSigY Or HomSigZ = True Then
        MsgBox("Home switch active...please deactivate before tool change.")
        Exit Sub
End If

If Xreferd Or Yreferd Or Zreferd = True Then
        MsgBox("Axis not referenced...please home all first.")
        Exit Sub     
End If

LastFeed=GetOEMDRO(818)

SetUserLED(1001,False)
SoftState = GetOEMLED(815)
If SoftState = True Then
DoOEMButton (119)
SetUserLED(1001,1)
End If

SetUserLED(1002,0)
WorkUnits = GetOEMLED(801)
If WorkUnits = True Then
code "G21"
SetUserLED(1002,1)
End If

DoOEMButton(104)
While IsMoving()
Sleep 100
Wend

xTSensPos = GetUserDRO(1200)                 
yTSensPos = GetUserDRO(1201)               
code "G00"                         
code "G53X" & xTSensPos & "Y" & yTSensPos     
While IsMoving()
Sleep 100
Wend

SensGapPos = GetUserDRO(1203)
code "G00"
code "G53Z" & SensGapPos
While IsMoving()
Sleep 100
Wend

zTSensPos = GetUserDRO(1202)
SensSpeed = GetUserDRO(1204)
code "G31Z" & zTSensPos & "F" & SensSpeed
While IsMoving()
Sleep 100
Wend

CurrFixture=GetOEMDRO(46)

Select Case CurrFixture
Case 2
     ProgXZero = GetUserDRO(1209)
     ProgYZero = GetUserDRO(1210)
     ZtoProbe = GetUserDRO(1212)
Case 3
     ProgXZero = GetUserDRO(1213)
     ProgYZero = GetUserDRO(1214)
     ZtoProbe = GetUserDRO(1216)
Case Else
     ProgXZero = GetUserDRO(1205)
     ProgYZero = GetUserDRO(1206)
     ZtoProbe = GetUserDRO(1208)
End Select

SetDRO(2,ZtoProbe)

code "G00"
DoOEMButton(104)
While IsMoving()
Sleep 100
Wend

code "G00"
code "G53Y" & ProgYZero & "G53X" & ProgXZero
While IsMoving()
Sleep 100
Wend 

If GetUserLED(1001)= 1 Then
DoOEMButton (119)
SetUserLED(1001,0)
End If

If GetUserLED(1002)= 1 Then
code "G20"
SetUserLED(1002,0)
End If

SetOEMDRO(818,LastFeed)

End Sub 

A friend of mine with the same machine and screenset just got his smooth stepper and is not experiencing the G00 problem that I am. It is a real pain editing these moves out of my toolpaths.
Is there perhaps some setting that I am missing? I would love to get this resolved since I use my mill daily.
Not griping...I love the SS, but would love it more without this problem.