First off I think some of you have it backwords.
1) A Ported box takes less power to make the same volume as a sealed box. (hense louder)

2) The same sub in a ported box requires a larger volume. Partially to make up for the port.

3) A sealed box is heard farther away. Sealed box can be projected where a ported box uses the volume and accoustics to produce the low frequency. Open the trunk with a ported box and some bass goes away. Doesn't seem as loud.

4) Sealed boxes are more "accurate" than a Ported box. Mainly on the basis of reproduction. Although, ported boxes have have a higher transient response (It can recover faster, therefore can reproduce very quick repetative notes). Sealed boxes are punchier but I would not say tighter bass.

5) Ported boxes can produce slighly lower frequency than sealed.

Overall each sub has its own characteristics. Most subs work best in the biggest box you can make for a trunk. So my advice is to buid the box, and then if the sound does not suit you and you want to port it, you can do so then with the proper measurements of ft3. I am waiting for someone to design a closable port to make a sealed or ported on the fly.

I use WinIS Beta.
Or the directions from the manufacturer.
Parts Express is excelent for any parts that you may need.