I would say MSI are on par with Sapphire, quality wise and the like. Their products normally get rated very highly (especially their lightning version of cards). Based on the plain Tri-x 290X, I'd say the MSI will be slightly warmer (a few degrees), but the VRMs will probably be cooler (how important that really is, I can't say).
That said, I'm not on commission from MSI or anything, so I don't really care too much if you opt for a different card 😀