5x5 question

so i started the madcow 5x5 i couple weeks ago and im wondering once your a few weeks in and breaking your 5rm's should those last reps be very difficult? 

logic tells me it should, but i just can't imagine improving so fast. 

i guess my question is since i haven't gotten to my 5rm max week it hasn't been too hard, but once im adding weight past my 5rm it should be really tough right?  like almost on the verge of not being able to finish? 

are you doing the advanced or intermediate?

6'3"  @213

Squat 1x20x275

press:200, Deadlift:475, Bench:300, P.clean:235, Squat:385

"The only failure that is final is to stop trying to improve"

intermediate

It's amazing what following a well-thought out program like that that has you squatting 3 times a week can do for you.  I wouldn't be suprised if you continuously hit PR after PR for a few months straight.

"True genius, in many fields of human endeavor, is often revealed in elegant simplicity."

- A smart man

Journal: http://www.wannabebigforums.com/showthread.php?t=117358

pan im doing my own 5x5 and ive hit maybe 30 prs in the last month breaking all sorts of squat and leg press as well as cardio related ones  :P

219 weight trying to lower 217 now. 2 months later. lol.
250 bench
305 squat
345 deadlift