What amp rating do I need in a corded hedge trimmer?

Across the reviewers we read, 3.0–3.2 amps is enough for soft new growth and shrubs under ~1/2 inch, 4.0 amps handles most residential hedges and branches up to about 3/4 inch, and 4.5–4.8 amp motors are reserved for thicker, woody growth. Retailer reviewers consistently note that under-powered trimmers bog down in older holly, privet, and laurel.