The short version
Khlong Toei is a working district with a remarkably central position. The port, market, railway and dense residential lanes sit beside offices, luxury towers and the green space of Benjakitti. It is a choice for someone who wants Bangkok as it is rather than as a master planned compound, and who will inspect the exact street carefully.
Where the map misleads
Sukhumvit Road is close, but the district is not all polished high rises. Khlong Toei market and the lanes around it are busy, intensely local and practical. Towards the river and port, roads become more industrial. Around Queen Sirikit National Convention Centre and Benjakitti, the urban landscape is more spacious, but the routes between pockets can be awkward on foot.
Getting around
The MRT Blue Line serves Khlong Toei and Queen Sirikit National Convention Centre, while BTS Phrom Phong, Asok and Ekkamai cover the northern edge. Main road traffic is persistent. A home near rail can work without a car, but the district’s internal trips are often easier by motorbike taxi than by walking.
The verdict
Khlong Toei rewards residents who want markets and centrality more than visual tidiness. It is not the obvious family choice, though older children may appreciate the independence. I would choose a quiet lane with a short route to the MRT, and avoid paying a premium simply because a listing photograph includes the river.