There are different benefits to all three ways of getting Actemra.

I have done all three ways at various times. I started with injections every 2 weeks to "play it safe" as my rheumatologist said. I was able to taper off prednisone doing injections every 2 weeks. However, within two weeks of tapering off prednisone for the first time in 12 years... I had a flare but not a PMR flare.

A different biologic was tried called Humira and 60 mg of prednisone was restarted. Humira didn't control my PMR pain. I got stuck on 15 mg prednisone again and couldn't taper any lower.

I switched from Humira back to Actemra but my rheumatologist suggested weekly injections instead of every 2 weeks might work better. Weekly injections of Actemra worked better. I tapered my prednisone dose from 15 mg to zero in about a month and got off Prednisone for a second time.

I did well on weekly injections of Actemra until a supply shortage of Actemra happened. Existing supplies of Actemra were diverted to seriously ill Covid patients. I didn't get resupplied with any Actemra injections for about 6 months.

When Actemra was restarted, I was in a world of pain even with 20 mg of Prednisone. A synovial cyst had formed on my lumbar spine in spite of me being on prednisone. A lumbar spinal fusion was scheduled to fix the problem except I had to be off prednisone. Additionally, I had to be off Actemra for a month before surgery and a month after surgery. There was no way I was going to be able to go 2 months without an Actemra injection.

My rheumatologist suggested that I switch to an infusion of Actemra. The time between infusions is normally 4 weeks but it might be possible to go 2 months between infusions. I did infusions for a year. I was able to go 7 weeks between Actemra infusions. The spine surgeon said 7 weeks would be a long enough time to do surgery. My back pain was much improved by this time. In preparation for my lumbar fusion, another MRI was done. The synovial cyst that had formed was gone so surgery was postponed. I stayed on Actemra infusions which I have done for about 3 years. I currently do an infusion every 4 weeks and that works the best for me.

I did some research about synovial cyst formation. While degenerative changes of the spine are the primary cause --- it turns out that the fluid formation is an inflammatory process. My rheumatologist said that Actemra very likely stopped the inflammation and the synovial cyst was reabsorbed.
https://www.spine-health.com/conditions/spinal-stenosis/synovial-cyst-lumbar-spine