Collet size is the fitment and it fixes which cutters the machine will take. A 1/4 inch collet covers most workshop cutters and keeps the tool light. A 1/2 inch collet takes heavier cutters with more shank behind them, which is what allows a large profile to be cut without chatter.
Power follows the collet because the two are matched by design, with the 1/4 inch machine at 1200W and the 1/2 inch at 1800W. Variable speed then matters because cutter diameter changes rim speed: a large cutter at full speed turns far faster at its edge, which burns the work and shortens the cutter. Dropping the speed for a large diameter is what the variable control exists for, and it shows in the finish as much as in cutter life.
A trimming router is a different tool rather than a small router. At 710W it handles edge work and laminate trimming where a full size body would be unwieldy, and a 20V cordless trimmer covers the same job without a lead. Weight and length are stated on nine of the ten lines.
Micro carbide burrs at 3mm cut metal and hard material by grinding rather than routing timber, which is a different action from anything a router cutter does. Profiles held are ball, ball nose cylinder, ball nose taper, pointed tree and ball nose tree, each in packs of three, with a five piece set covering the range. Questions go over WhatsApp on 07754288583. Individual burrs are bought as they wear rather than replacing the whole set.