Spain from Malaga to Madrid

What are your concerns that you are looking for input on?

It's not like you don't have choices; there are a ton of non-stop trains from Malaga
to Madrid on most days, from multiple providers.

For a 2-3 hour train ride, I would not get too worried about the various providers,
but someone else may be able to provide more input on Renfe Avlo vs Ouigo vs Iryo
vs Renfe Ave.

I can say Ouigo is a low-priced option, and if you're concerned about a crowded train,
picking 1st class on Ouigo may be no more expensive than 2nd class on other providers.

OUIGO has only second class. You can pay for an inclusive ticket, but you still will be in a crowded train car.

I have just sorted my winter plans and flights and will be traveling from Madrid to Malaga. I asked the same questions as it my last visit was only a Renfe option.
There are 3 companies, oiugo is budget, crowded and noisy and have luggage limitations. Excess luggage is extra costs.
Renfe offers discounts or combos for such as Tarjeta Dorada foe over 60s or discounts for multiple people. It also offers 2 classes of train and some have quiet cars. More generous for luggage amounts and space.
Iryo is independent and the more luxury option. It and Renfe often have cafe cars.
Renfe releases their trains theoretically 90 days out, but it could be as few as 30.

Thank you a million to each of you who wrote back so helpfully to my question about trains to and from Malaga/Madrid!