I roast my own coffee (as well as make my own beer and have become a bit of a wine connoisseur). There is a huge difference between what you buy at the grocery store and what you can get by roasting yourself.
First off, all grocery coffee is stale. Roasted coffee stales in about three to five days after roasting. There is a point between twelve hours and three days that the coffee is typically at it's peak flavor.
Second, many store-bought coffees are not all Arabica beans, which is the most flavorful type. Many grocery brands are cut with Robusta beans, which boosts caffeine and can be grown at lower altitudes and better harvested with machinery.
Organic or not, the best coffees can be found at small coffee farms, where attention to detail both in cultivation and cherry selection. Most of what I buy comes from a lefty group known as Sweet Marias (www.sweetmarias.com). I don't question their politics - I just enjoy some of the best coffees the world has to offer. You would be very surprised at the variety of tastes and flavors you can find between different origins and farms.
This is my roaster:
It's a nice hobby, and the best thing is - like beer brewing - you have something very good that not many store brands can duplicate.
I don't recognize what make of roaster that is, but I do remember trying to use an AlpenRost as a sample roaster.
Terrible results.
That was back when I roasted about 20 bags a month on larger roasters (but not so large they didn't still qualify as what is termed "small batch" roasting).
Am not in the coffee biz, anymore, but I do miss the variety. I don't miss that sorry excuse for a drum roaster, though. As a 'sample' roaster, it was no good. I could never get rid of the plastic taste. Lining the small dump bin with foil might have helped.
Never buy an AlpenRost --- not of the vintage pictured, anyway. I could do better or as good, in a frying pan over an open fire.
I see the one you have has a cooling bin. I'll assume it's air suction cooled, much as larger roasters. It appears there may even be a thin, narrow sweep at the bottom? I can't tell from the photo, but passing under the beans, lifting & stirring a bit would be good.
What kind of overall time profiles do you use? A bit less than ten minutes? 12?
I've gotten the impression that with micro batches, shorter roasting times than typically used with actual commercial roasters, is better.
Trying to match the roast profile I used in larger roasters would tend to 'bake'. I found that out when using a 30 Kilo machine, roasting both large, and smaller amounts.
The larger batches would develop well under a certain profile...trying to match that profile, in the same equipment, with a load 1/4 the weight, wouldn't give identical results.
The smaller loads not only would want to roast faster, but liked it, too.
But then again, there are lots of variables. Air temp, air flow volume, what the radiant heat transfer rates of both the drum itself, and the individual coffee are like, etc., not to mention moisture content of the bean, in the first place(!)- bean density & size, all enter into the equation.
As far as your claim that roasted coffee is "stale" after three to five days, most pros would differ on. It outgasses for about three days.
And yes, I typically always like it best right out of the roaster. (I should have ALWAYS cupped the next day, avoiding the initial out-gassing, but I didn't)
I've probably brewed thousands of cups that way, snatching a handful from the cooling bin. BUT --- some coffees & blends actually mellow out after a few days, even a week, with the overall cup improving as harsher edges sort-of round off. Been there, done that. Heavier bodied coffees can tend that way...