For things like 1/16th note patterns, as @t mentioned, the envelopes trigger differently.
The result is a less static playing of the sound. When you compare a 16th note hat pattern on a sampler, using a single sample, versus the real deal analog drum machine, the difference is striking. The sample has the sound of a CD skipping, as there is no variation with each hit. LFOing some parameters helps but it doesn’t get you there 100%
So, one thing you can do with OT is set up sample chains where all the samples in a chain are of the same instrument. Record 16 different hits of the same 808 hi hat, put them in a chain, and during playback, use a random LFO for sample slice select. aka “round robin”
It’s a nitty gritty detail, but worth it if the sound of a static sample annoys you.
And that’s just one characteristic of the sound of an analog drum machine.
When I am on my Acidlab Drumatix, programming closed hats, open hats, and both on the same step (which produces a unique sound) plus working their decays, plus working the accent knob, all at the same time, you just can’t mimimc that with anything else. Especially with a bit of swing added in.
So a lot of folks are hyped about the RD808, because to get this in a $299 drum box is a great value.
The Cyclone TT-606 was $299 for many months, and I bought my second unit during that time, it also has the accent/analog/swing funk in spades.