seems like nowadays turbo timers focus on everything else BUT just a basic countdown,, can you imagine how cheap a turbo timer would be if it would just count down and then shut off (with the ebrake safety switch of course)? they'd be like 25 bucks.
but it all depends on how u wanna play with it
greddy - program ur own songs, make the LED's dance around (if you get the clear one), battery voltage, 4 count down settings/modes, etc etc etc
apexi - all what that guy said
blitz - seriously, do you NEED A LAP TIMER??? lol
ive messed with the hks one(i think it was that one), it at least has a boost meter/warning on it, seems reasonable, if you put it somewhere where u can see it change colors

they all count down the same, pick one that has the "goodies" you want..............good luck