A tele converter simply magnifies the image. Right ?
And, for the highest quality results, you must use a lens without a converter. That said, there is a good reason to own one, and to make good pictures with them.
Start with a good prime lens and you're far better off. Nikkor converters are pretty inexpensive used, and do a good job. Converting a long lens is more successful than a short lens. So, if you want to magnify the image of a Nikkor 135, I'd say you've got a pretty good case for success.
Follow the same rules for shooting a 270mm lens ! Tripod or fast shutter speed, suitable subjects, and good quality converter. The volume of good used Nikkor stuff on the market makes the case for a TC 200 / TC 201 ( for AI-S lenses and to use Matrix metering ). For a 2x for lenses longer than 200mm, use a TC 300 / 301.
As always, the advantages of using Nikon gear begins with optical quality, but ends with reliability and ease of use.
I love long lenses but use them seldom, and almost always for the long-reach pictorial scenic. I carry a 180 in my bag, and a TC 200.
Youll probably be quite happy with a TC 200.