WOW it really is impressive to see how much better SLC is compared to MLC ! The Intel X25-E lacks TRIM but has a WA of 1.1 and 50nm SLC NAND. A M4 has TRIM and WA of 1.1 and 34nm MLC NAND. Sandforce often has actual 0.6 WA which is very nice and TRIM too etc. Capacity also plays a role here. For example a 64GB X25-E will last twice as long as a 32GB X25-E !

Imagine the almost ideal scenario for SSD endurance ( which does not exist currently but the technology is there ) : 90nm SLC NAND, 256GB capacity ( tons of reserve space too ), WA of 0.6 with compression controller like Sandforce and TRIM too etc.