Some casual kilts are cut with patterns that are fairly different from a traditional Scottish kilt. For example, on the Utilikilts I own, the pleats go all the way around, with the apron hiding those in front. I've found that this design, combined with the narrower apron, makes it a bit easier to "stay decent" in many circumstances, especially when sitting down and getting up, although your mileage may vary.

Casual kilts are often machine washable, whereas traditional Scottish-type kilts are often not. In some cases, namely with my Original-model Utilikilts, I've had adequate success machine drying them as well, although I should note this was not officially recommended (by the Utilikilts company), and does not seem to work well with other model Utilikilts. Some Scottish-type kilts are, however, machine washable, and look very nice. I have a "Semi-Traditional" tartan kilt from USA Kilts which is machine washable and looks great. Because of this convenience, I tend to wear it a lot more often than I do a wool kilt, which takes more effort to clean.