I've now been to Shiki twice - once a few weeks ago with a friend and again this Saturday night, solo. The food was interesting and fresh, the service was attentive and far speedier than what has been described in earlier posts (are they listening?) and the atmosphere was peaceful, belying its subterranean location.
I had the Tuna-Nagaimo Tartar both times. The fish was super fresh and the presentation was artful (a quail egg in shell in the corner of the dish, held in place with wasabi, for pouring over the chopped raw tuna and nagaimo and mixing with garlic mirin sauce). This was a substantial dish for only $7.50. Ebi mayo is grilled (not fried, despite the menu description) shrimp served over a honey sauce and drizzled with spicy mayo. It sounds a bit odd, but the flavors mesh beautifully, especially with a little squeeze of lemon over the top. Last, the Sea Eel Millefeuille (broiled sea eel combined with grilled nagaimo, vegetables, and poached egg) was solid, but not as transporting as the other two dishes.
I also had an order of toro sushi. Shiki has a full nigiri menu, though the small plates are the reason to come here. That said, the toro was melt in your mouth fatty, with two thick, oily pieces for $14. The same quality toro at Fugakyu is $22.
I need a larger group (hound destination, anyone?) to try more, otherwise I'm just going to have to devour the rest of the menu in stages.....