I've been using Karcher K4 Basic for a year. Weekly car wash and also periodical compund/patio cleaning. Still going strong after a year of abuse. If i do my patio cleaning, it could be continuous running for 10-15 minutes with small duration of resting time where i move the K4 unit to another supply corner.
One thing i like about Karcher is there are plenty of accessories to go around to ease the usage.
So far my best accessories to pair along for my usage:
1) VP180S Elbow Vario Power - for shorter lance and angle tweaking flexibility.
2) Snow Foam FJ6 - Snow Foam Lance (not so strong with foam, so i use this for secondary car wash detergents)
3) MJJC Foam Cannon - Strong snow foam from third party brand. Superb for my prewash snow foaming.
4) China brand patio cleaner that looks like T-Racer with fraction of price from Karcher originals.
5) China no brand 15m high pressure hose to replace the original 6m high pressure hose.
The cons with this K4 is there's no proper place to keep your accessories along with the main unit. Only 1 small meshed pouch behind to keep everything.
So you have to be creative to keep everything together.
soon you will see internal slow leak, not running but have water dripping out the base, too much plastic