First off, I both keg and bottle. Kegging for the daily drinker and bottling for sharing (full batch) and Big Beers. Bottling is NOT a time consuming process compared to kegging if you exclude the time it takes to delabel and clean the bottles. This is made easier by buying bottles that haven't gotten a bunch of moldy scum on the bottom. I can bottle a 5 gallon batch in under an hour easily.
Kegging definitely costs some up-front money. But, if you are into homebrewing and drinking beer, it's a definite advantage for a couple or reasons:
You can bottle easily from a keg with no special equipment needed.
Growler fills...
CO2 on hand for purging headspace.
CO2 system for carbing anything that doesn't have yeast!
Kegs can be jumpered for clean beer to take to parties in a keg. Try that with a bottle!
Just keep in mind that until you get a goof feel for a kegging system, there could be a bit of trial and error to get it balanced and pouring good beer. Nothing that can't be overcome, but line length and diameter, pressure, temp, etc. all combine to make kegging a joy when done right.
Kegs still need to be cleaned but they are usually faster and easier to clean than a whole batch worth of bottles. You have beer lines and faucets to clean.
Overall kegging probably does save time, especially when you can swap kegs often. When you have to clean them every batch (2-3 months) like I do, it's less of an advantage. I think if you have the $300-400 to spend for a basic system, go for it. The advantages outweigh the cost. If you don't think you brew often enough to make it worth it, you should be able to shave you bottling time down to under an hour easily once you have a good supply of clean bottles.
Revvy has a nice thread with tons of bottling tips.