Cash, the features you're refering to are for the original Mo, dude is interested in the ES model.
The Motif ES doesn't come with any memory but can be upgraded to 1gig.
In my opinion the sampler on the ES is not too bad at all, it's way better then the MPC sampler. My biggest complaint about the ES was lack of a sample audition feature. While you can audition sounds once they're in memory that doesn't help when you have tons of samples with similar names and want to find the right one quickly. You have to load the sound and trigger it to see if it's the one you're looking for. The other drawback to this board is the interface, it's tiny. It works but it's not nearly as easy to get around in as the Triton and Fantom s.
The real meat of this board is in the sounds, as Cash said, if you're looking for auhtentic bread and butter sounds then the Motif is definitely the way to go. As far as the sequencer, I myself didn't find it difficult at all to work with but if you've never used a Yamaha board before it might be a little confusing at first. To me the Motif is the most complete "workstation" out there(at least for the next month or so, the Triton Extreme and Roland Fantom X look nice). You can do a complete song from start to finish(except for the actual burning of a cd) with just the Mo, including vocals, overdub vocals, etc. I won't get into how this is done but if you're looking for an all in one package the Mo ES is the way to go(or a Triton Studio). If all you need are the sounds then I'd say go with the Mo rack.