I have used my former go to razor a Trac2 on a very few occasions since returning to "traditional" shaving. I see no advantage to or reason for using a cart razor again, other than for flying. I don't see the shaving time being any different. I can easily shave as fast with my DE's of choice, one of which is a Maggard slant, as I can with a cart. It's the prep time and multiple passes that makes my DE shave take a little longer, but turn out oh so much nicer. If I use the same prep method and number of passes with a CART the shave takes just as long as my DE shave, but it still doesn't come out any smoother, more irritation free or cheaper.
I fly every other week, on average. -- Pitralon forever - Real pens have a nib - If it doesn't tick, it's not a watch.
If you haven't already, stop on over to the Barbasol Brotherhood thread (or even the Adulterated Barbasol thread. Plenty of relapses over there...oh wait...I mean memory lapses.
Harry's is a fantastic company and I love their razors. If I had to go back to cartridge shaving they would be my #1 choice.