I have the following sizer-lubricators:
Lyman 450 (1)
RCBS (1)
Seaco (2)
Star (4)
For ease of sizing and lubing, the Star can't be beat, but it is expensive. I believe it's money well spent if you're going to be doing a lot of bullet casting. Sizing dies are available from Magma Engineering, and original Star dies are for sale on ebay all the time, but people are bidding them up way over new die prices for some reason. With the Star you only need the flat punch, and feed the bullets through nose first. The bullet is pushed all the way through the die and drops out the bottom, so you only handle it once during this process.
The Seaco is my second favorite sizer-lubricator. It's a precision made tool, and does a great job, but like the Lyman and RCBS, it's a down and up process. You push the bullet down into the die, where it's sized and lubed. Then on the upstroke of the handle you raise the bullet back up and remove it.
The Lyman and RCBS work the same way, and the new Lyman comes with an optional base heater, so if you're sizing in cold weather, or using one of the hard lubes, you just plug it in and wait a few minutes for it to heat up.
I use both hard and soft lubes, depending on what I'm going to use the bullets for. For me, a heater is a necessity, especially for the Star machines, where I'm sizing a couple thousand at a sitting.
What it boils down to is how much are you going to be using it? If you're going to be making thousands of bullets at a time, then the Star is the way to go. If your production is going to be less than that, then any of the other machines will work for you.
Hope this helps.
Fred