I've been using one of the Lee 20 lb pots for the last couple of years and probably have 3-4,000 or so bullets through it.  I had previously used both the 10 and 20 lb. Lyman bottom pour pots.  I find the Lee easy to use and pretty consistent with its temperature, but it is a little spindly looking compared to the 20 lb Lyman, and the dump lever is a little light, so I had to get used to a new "touch" on the way I operate.  I would like to have my old Lyman back (I guess) but I really don't feel disadvantaged with the Lee, and the $$$$ difference was quite significant.

Froggie

I used the Lee 10 lb. for years, but somehow misplaced it. I bought a new Lee 20 lb. last year and I am glad the 10 lb. got "misplaced", as I love the 20 even more!

I had both the lee and an rcbs. and I finally got rid of them and went down to academy bought a deep fryer and a bottle of gas a nice dutch oven and boys not only can I keep up to #60 of lead at 700 to 750 all day it is a lot easier and cleaner.
irish

Buggy Builder,
  If you are new to casting bullets, I don't know if you've read the Lyman Cast Bullet Handbook, but it's a great place to start your adventure. Alot of good solid information and advice in there. It's probably easier than sorting out advice you get here, but still, ask questions if you're having problems.  I ladle cast, but no matter if you are a ladle caster or a bottom pour kinda guy, temperature control is as important as your alloy, and the Lee magnum pots deliver this feature in spades, at a very good price. 
  As far as stirring the lead, that's a good practice no matter what. Cleaning dross off the top isn't as critical with bottom pour as it is with ladle casting. You still should flux and skim dross off at the beginning of a casting session.
  As far as adding lead or tin, if you purchase alloys in a certified mix like 20:1 or 30:1, you shouldn't have to add tin, as long as the mould will cast a desired diameter bullet in a specific alloy. If you look at any of the custom mould makers websites, they will ask you what diameter and weight bullet you want and what alloy you will be using. You will get a mould that casts exactly what you want. If you are casting with wheel weights, linotype, or hospital (isotope) lead, you will have to do some refining with tin or pure lead to get a proper bullet weight and diameter.
And yes, you can cast with the dust cover removed.
Wild Bill

The only problem my Lee has ever had in twenty years was a failure this spring to heat up enough to melt lead.  All it needed was a cleaning of the electrical contacts on the heat control unit.  Automotive electrical spray and a little touch with an ignition point file (remember those?) took care of it.

It makes me think that a regular cleaning my be a good idea to help it keep a constant temperature.

hms50