Micro stuttering is a feature almost exclusively linked to low budget cards. I have never seen micro stuttering on any card in SLI from the top 3 tiers.....
760, 770, 780 ...nada
660 Ti, 670, 680 .... nada.
560 Ti, 57, 589....nada.
Since the 5xx series, I have done more x60 SLI build than x80 single builds by far..... with the 560 Ti being $205 and the 580 at $500, you got 40% more performance for 80% of the cost of the 580..... NVidia saw that and adjusted pricing accordingly as the 580 kinda bombed once the public picked up on that. That performance / cost ration made the 560 series the best selling DX11 card ever till recently when it was passed by the 660 IIRC. I'd say that since the 5xx series, about 6/10 builds I have been asked to do were SLI with most o the single card ones being single cards solely because of budget considerations ..... every one of them had SLI capable MoBos and PSUs
As for heat issues, if ya stayed away from the reference cards and the SC series, you were generally OK as long as ytour PSU, case and cooling were selected accordingly. Now however, with nVidia's new reference cards, you see some manufacturers dropping their custom PCBs and using the new reference one. MSI for example has the top rated 780 Ti (9.9 per TechPowerUp) with the rating to a large part associated with it having the best balanced cooler available from a heat and noise perspective.
If you into water cooling, most WC builds are have at least 2 GFX cards.....my cards are running at 39C under Furmark.