I played my last game in steel toed boots. While the ankle support is there, their weight made it more fatiguing. It may also be uncomfortable on hilly or uneven terrain.
A good pair of boots is on the top of my list right now.
H&K G36c (KWA) / Glock 18c (TM) / Kimber LAPD SWAT Custom (TM) / Mossberg M500 (ACM)