If all you're going to do is mame, you want too sharp an image, like what others said.
If you're going to word process or (especially) program a lot, you're right in looking for the best text contrast. Don't have either monitor, but I doubt the IBM has much more than the sony. That said, you better look up some monitor reviews that compare text outputs for the best info.
If you want to do both, remember text sharpness is only slightly related to image quality; they are almost always separate qualities reveiwed.
FWIW, I like my iiyama, but have heard the quality/price ratio isn't as great as it used to be. Sony & IBM are rarely low cost.