I just replaced the inserts only on the original wiper arms ... the OEM inserts lasted 7 years, and that's unmatched by any of the aftermarket blades I've used on my 4Runners (and I've tried most of the major aftermarket blades on my Toyotas over the last 21 years).
The OEM Toyota inserts are extremely soft and compliant, they feel like a silicone compound.
If you do decide to try some aftermarket blade assemblies, DO NOT throw away your OEM arms. If you are not satisfied with the aftermarket stuff, you can always just buy the OEM inserts, stick them in your original arms, and revert to original performance.
The OEM Toyota inserts are extremely soft and compliant, they feel like a silicone compound.
If you do decide to try some aftermarket blade assemblies, DO NOT throw away your OEM arms. If you are not satisfied with the aftermarket stuff, you can always just buy the OEM inserts, stick them in your original arms, and revert to original performance.