I recently visited the Berea Location, and was impressed. The previous occupant was a decent Chinese/Vietnamese joint, but Sweet Mango is a welcome improvement. They renovated the interior and really classed the place up, and on a Friday at lunchtime, it was pretty busy but the service was very good.
The food is among the better Thai I've had in Cleveland. The Duck Choo Chee was especially nice in that it was breast meat only (No Bones!) and the Pad Thai was a solid contender as well. Both dishes were pleasantly spicy (per our request), though I would assume it would be possible to get them hotter or milder if that's your thing. The Mango Summer rolls were tasty, and the fried banana dessert was phenomenal.
I visited with a co-worker who was completely unfamiliar with Thai cuisine, and she was thoroughly impressed as well. Great stuff!