Will the type / brand of firebrick effect stove performance?

Do the different brands of firebrick make your stove burn different? I would assume soapstone would be one of these that would change the way things work but what about the different densities of the brick? My Osburn 2200 insert had two brick in the back of the stove that cracked I think it was from me loading end to end a little to rough. But the brick is kinda light and somewhat pours almost like lava rock on your grill. Anyway I decided to replace the back and sidewall brick with ones that I got at Menard's. The new brick is heaver in weight and more dense but it almost seem like I don't get the same amount of heat from the insert. Is it possible that more heat is going up the stack because it cant go through the new brick as well? Or em I just dreaming? It still is cranking out good heat but it seem a little different. Any ever experience anything like it??

Thanks MSG Like kd460 mine were just cracked but I decided to do something about. Looks like I may have done the wrong thing though. I saved all of the pumas brick that I took out so I may just put them all back in except the two that were cracked (I did throw them away) We are to get a warming trend this weekend. Hay KD poor Mannie had a shell shocked look on his face when they pulled him after 3 goals. I'm a wings fan but its to bad it was such a blowout on Brett Hall night. I will be at the game on Thur night at the Joe to root them on and have a few cold ones!

That is odd.. Did the dealer put the stove together? My stove has heavy brick on the bottom of it and the top and sides have the lighter ones. Stove is working fine but I might put the OEM brick back in the side just to see. I did this at the beginning of the season so its is hard to compare from last year. I have CRS (cant remember sh--t)