Which is better for a marathon?

The Adios Pro 4. Its plate and Lightstrike Pro foam are built to hold pace over 26.2 miles. The EVO SL is fine for finishing a marathon but gives less propulsion.

Can I use the Adios Pro 4 for daily training?

It works for tempo runs, but the foam and plate break down faster with daily mileage. Most runners keep it for workouts and races and train in something like the EVO SL.

The EVO SL. Its EVA-based foam and standard rubber outsole handle high weekly mileage better than the Pro 4's race compound.

Is the EVO SL worth stepping up to from a basic trainer?

Yes, if you want a neutral shoe with forefoot cushioning and a 6 mm drop that can cover most runs. It is a clear upgrade over entry-level trainers without being a race shoe.

Do they fit the same?

Both are neutral with a 6 mm drop and a regular width. The Pro 4 uses a men's-specific last, while the EVO SL is unisex, so check the size chart before ordering.

Which is better for a heavier runner?

The EVO SL. Its softer foam and more stable platform are more forgiving. The Pro 4's firm, plated ride suits lighter, faster runners.

adidas Adios Pro 4 vs adidas Adizero EVO SL

Buy the Adios Pro 4 for race day and fast tempo work. It is the lighter, more aggressive shoe, with a carbon plate and Lightstrike Pro foam built to hold pace over 10K to marathon. The EVO SL is the better daily trainer: more forgiving, more durable, and rated 4.8 out of 5 across 7,038 ratings. Owners of both describe the Pro 4 as sharper and the EVO SL as the shoe you can run in every day.

Choose the Adios Pro 4 if you race or do structured speed sessions and want a light, plated shoe that rewards a fast cadence.
Choose the Adizero EVO SL if you want one neutral road shoe for most runs, with more comfort and durability than a pure racer.

Prices

adidas Adios Pro 4: $302.00 at Lovell Sports (last seen Nov 9)
adidas Adizero EVO SL: $75.00 at Finish Line (last seen Nov 12)
Difference: the adidas Adizero EVO SL is $227.00 cheaper than the adidas Adios Pro 4 at the latest prices (Nov 9 and Nov 12)