My wife and I have gone to Tenkai for nearly 3 years now and just keep going back, often about once a week - it's just that good. The restaurant is relatively large so you don't feel you're eavesdropping on the table next to you and the music is kept at a good volume so you can have a relaxing conversation - unlike many "trendier" sushi places.
The sushi quality has always been great - I usually go for negitoro rolls, tekka don, or chef's nigiri, but have tried most things now. Their starters are very good, especially the gyoza.
The staff are always very friendly (both the old and new management) and although the waiting staff are sometimes a bit casual, they are friendly and competent.
I have found that this is a great place to introduce people to sushi and Japanese food in general. My parents loved the teriaki and donburi, and my wife now experiments with sushi rolls and hamachi.
Maybe not as trendy (or loud) as other local sushi bars, or as sophisticated as those Downtown, this places offers real value for money in a quiet and comfortable environment