What would be the best way to render this sentence in Russian so that it doesn't become clumsy and tautological?
This is one of the main services and features of the product.
The problem here is that services and features (the way they're translated) are of different genders in Russian so the numeral one must agree with each of them in gender.
The most straightforward way of rendering it would be
Это один из основных сервисов и одна из основных функций изделия
but the structure один из... isn't usually repeated in relation to the same object, and that makes the sentence unnecessarily pleonastic.
In a movie "Контрабанда" (1974) there's a phrase affected with a similar problem of disagreement, although a bit more forgivable
Одна из самых аккуратных и дисциплинированных членов нашего экипажа.