The '26' is because it is in the 26th sub soi of Ramkamhaeng.
It is a mostly Thai area, also with a big University.
It depends what you want it for, rental/investment or for you to live there.
If it is for you to live in, where do you have to go for work? This is far from the main Sukhumvit area, so only useful if you work in that area. There is a lot of traffic in this area and no BTS/MRT at present (coming I believe).
If it is for investment/rental, it is an OK area as many Thai's to rent it and also many Uni students. You would need to check the rental values of the building at the noticeboards in the building or online. It will not be high rental rates.