The lighter the luggage the easier the journey.
With smart packing and judiscious use of hotel laundry services a 30 litre pack + small satchel is comfortably enough for a 2 week round the world business trip spanning three different climate zones. Suitcases are for suits, check-in is for suckers.
If you have no choice but to pack heavy North Face duffels last for years and (in black) are pleasantly anonymous whether tucked in a luggage rack on the trans-Tibetian express or rotating around the LAX carousel after you’ve been randomly selected for further interrogation by US immigration officials. The duffel also functions as a decent ad-hoc seat should your train/boat/pack-mule be delayed.
If you need to over-protect your laptops, camera gear and other fragiles Pelican cases stand up to pretty much anything a trip can throw at them with the 1630 model being being large enough to clear a path through Delhi airport and small enought to pop into the trunk of an Ambassador Taxi. The downside of using protective gear is that it’s heavy and tends to attact the attention of customs officials.
Finally, Granite Gear makes super light and versitile stuff sacks and pack liners for splashproof protection for equipment and paperwork in the field.