I have the 5-gallon Tetra Crescent corner tank and it's my absolute favorite by far. Its resident is also super happy.
What I really like about it is the LED lighting because it's really energy-efficient and makes the tank and its inhabitant(s) look even more gorgeous at night. LED lighting is pretty expensive, so I think these Tetra kits are a great deal.
I also love that it's acrylic, which insulates better than glass (save on the water heating costs!) and doesn't crack/shatter as easily. And it LOOKS better than glass because it is crystal-clear.
The filter does take up a lot of space but you could always sell it on ebay and replace it with a smaller filter.
You might want to secure the lid somehow if you have a cat. Also, I wish it was better insulated so the heater won't have to work as hard.
The Tetra Crescent 3-gallon kit is about $43 on Amazon so I think you got yourself a pretty good deal there, for $25.