Yep, as you found out, stay away from Armoral products.
Meg's apc+ is great on leather at about 10:1 and weaker. Stronger than that and it's a gamble. Maybe even start at 15:1 or 20:1.
If you have access or know somebody that has a steamer, place a microfiber of the head a gently warm the leather up before doing anything. It's not necessary but helps a ton.
Spray the seat evenly (not allowing drips) and use a soft to medium bristle brush to lightly clean and agitate. If this isn't working you can either step up the strength of the cleaner and/or use a scrubbie pad to lightly scrub and agitate stubborn grime.
Next, find yourself a quality leather conditioner. I use Meg's D180 Leather cleaner and conditioner. There are some very high end detailers using this stuff on a daily basis.
I like this conditioner because it also has a very light cleaning ability. It helps remove any weird streaks or grime you left behind in the previous step. Use a microfiber applicator pad or towel and apply the product evenly to the entire seat.
Let the product dwell for a couple minutes to allow it to absorb into the surface, and then buff to a natural and beautiful finish with a dry microfiber towel.
You don't want shiny surfaces in a car. It looks cheap and creates glare while driving.
Hope that helps. Good luck!