No. it is pointless.
Incoming torrents typically consist of many, very small data-packets. If these are individually written to disk by the torrent client you will get a lot of small random writes all over the place.
(Bear in mind that the data-blocks in a torrent are send in fairly random order to your computer. You don't get them sequentially.)
In general a high number of small random writes isn't good for any harddisk and it even worse for a SSD. That is where the "torrent kills your SSD" idea comes from.
But in reality it isn't an issue:
First of all: SSD's are tougher than many people think.
The OS/filesystem will cache disk-writs to some extend anyway.
And most importantly the torrent client itself will do that even better:
Typically a torrent client gathers data-blocks together (in memory) in so-called "chunks" and flushes the chunks to disk when they are complete (or when a certain time-period has expired, like an editor auto-saving your document every X minutes).
In many clients you can even configure the size of that cache-buffer and the recommendation is to set it as large as feasible given the amount of RAM you have available.
This caching prevents wear and tear on the disk (for SSD and classic HD) and, on classic HD, improves overall performance by reducing disk-trashing.
Setting up your own RAM-disk isn't really needed. It won't add any additional benefit.
As I'm one of the programmers who did some work on libtorrent (used by many torrent clients) and also on other file-sharing programs that have similar caching requirements I know what I'm talking about.