Your clarification means a lot -- "baked" potato in the U.S. tends to be a whole potato cooked on its own, where the insides become fluffy and creamy, and is done with larger starchy white potatoes, or sweet potatoes work well, too.
Roasted potatoes, on the other hand, tends to be (in the U.S.) be smaller "new" potatoes, waxy potatoes, or even larger starchy potatoes cut up (eg, 'oven fries').
The starchy potatoes only really hold up well when roasting if it's very high heat or a short amount of time -- if you're going to be cooking them with the roast as there's going to be moisture in there, I'd go for a waxy potato (eg, Red Bliss).
As for the browning -- probably coat them well with oil, and if they're not brown enough for your liking when you pull the roast, as you're going to have to rest it anyway, drain the meat juices, crank the oven up to somewhere around 450F (230C) and leave the potatoes in for a few extra minutes.
ps. yes, I know a sweet potato isn't a potato. And I also tend to use Yukon Gold for just about everything, as it makes great baked potatoes, and roasted potatoes (although, not sure how well with a roast at the same time) and they're good in pot roast and stews if you don't add them too early.
If you're going to be using a ricer, just halve the potatoes -- you can then put them cut side-down into the ricer, and then press -- the skin will be left behind. (I'd still give them a quick scrub before boiling them, though). Of course, this is easier, but not necessarily faster as it'll take longer for the potatoes to cook through.
If you bake them, just clean, bake, then cut in half, and put through the ricer. (Again, not really that much faster).
If you're cooking red potatoes, even if you're not using a ricer, there's no need to peel them beforehand, as you can boil them whole, then rub the skin off with a dry towel. (of course, for red potatoes, they're always going to be lumpy, and have texture, so in that case, I tend to leave the skins on).
To reduce the overall time, if I'm going to be going for a smooth mash:
- Only use large potatoes. Save the smaller ones for applications where you don't need to peel potatoes.
- Cut the potatoes into slabs. There's no need to get them to cubes. I tend to go to about 2cm (~3/4") thick. Any extra cooking time is made up for by reduced cutting / transfering bits to the pot / dealing with the chunk that fell and rolled under the cabinet / etc.
- Start the water warming while you're peeling. You don't want to place the potatoes into boiling water, but you can take some of the chill off it.
- Toss a few cloves of garlic (whole, but paper removed, end trimmed off) in with the potatoes, so you don't have to season afterwards.
- Use stock rather than milk. I keep boxed vegetable and chicken stocks at room temp, not chilled, so I don't have to heat it up first to deal with the issues of it cooling down the starches too fast.
- Decide if the ricer's really worth it -- I get good results just tossing everything back into the same pot after straining, hit 'em with a potato masher, add some liquid, then go through a few more times. It saves a lot of cleanup, but it might not be exactly the texture you're used to,
Best Answer
The variety of potato used for mashing really is a matter of preference, and the style of product you desire.
Light, Fluffy Mashed Potatoes
The best potatoes for light, fluffy, very smooth and elegent mashed potatoes are starchy varieties, such as the US Idaho.
Dense, Creamy Mashed Potatoes
For dense, creamy mashed potatoes (which also hold longer), a waxy potato like a Red Bliss or a fingerling is more ideal.
Middle of the Road
You can also get excellent results with middle of the road potatoes which are between the starchy and waxy extremes, such as the US Yukon Gold.