LSI 9260-8i vs Adaptec 5805z

[base]

Hi folks!
Im about to buy a new raid card and it seems like ive ended up choosing between the LSI 9260 and the Adaptec 5805z. And i cant decide

It will be used in a lab & virtualization server(dual nehalem xeoon).
Probably it will run mostly kvm under linux, with guests of all kind.
Will be splitted to a system raid1 and some sort(havent desided yet) of larger storage raid.

As far as i have understood sofar(right or wrong) is:
5805z: Very stable and hasslefree overall and no need for ordinary bbu.
9260: sas2 and pci express 2.0 = newer tech, Atleast in some cases faster than 5805z.

The price for me = 9260 is minimally cheaper than the 5805z so no large difference in price.

What would you guys choose in this scenario and/or in general?
All pros and cons is appreiciated deeply!

 

[r_manic]

Hopefully someone else here has experience with either controller; I'm just bumping this up for everyone to see.

 

[paulcooperorama]

I am having huge issues with the Adaptec cards and single failed drives causing the array to collapse... kinda hard to believe that a raid 6 or even a raid 5 having issues with a single drive failure. I used to be a died in the wool Adaptec fan having had some REAL issues with LSI and their support but since they merged, bought or assimilated 3ware I would lean towards them. that leaning is due to the partnering of LSI with the likes of Super Micro and others for backplane support. oh that brings up another issue... what backplane are you gonna use? that is very important.