Enterprise SSDs should last a lot longer than desktop drives. IMO even a normal desktop SSD shouldlast at least as long as a mechanical HDD.
Using intel as an example-
Intel 520 series ('desktop' level)- MTBF is 1,200,000 hrs.
Intel 710 series ('enterprise' level) MTBF is 2,000,000 hrs.
You cant really compare MTBF between manufacturers, as different manufacturers have different methods to get a MTBF. That said, I know the that 'top end' desktop drives and many 'enterprise' level drives came with MTBFs in the range of 1,000,000 to 1,200,000 hrs.
SSDs arent great for swap space. They have a limited number of writes. Even the 'enterprise' level drives with eMLC ('e'nterprise MLC, modded for more write cycles than consumer-grade MLC flash) have a limited write cycle.
RAM is cheap, motherboards haev huge limits these days, just buy more.
Revodrive 3 X2 is not enterprise level. Because its using a RAID 0 setup its less reliable than normal SSDs. The nearest equivilent from OCZ that is enterprise is a VeloDrive. 300GB is currently $1500+. Its also slower than the revodrive 3 X2.
Enterprise doesnt come cheap.