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It spreads a lot (in my garden conditions at least) and is very hard to eliminate. Having said that it never gets huge, and once it gets big-ish it's quite easy to pull out the leafy growth (the rhizomes stay put when you do this though and will regrow). It grows easily through woodchip and gravel so it's hard to eliminate from paths.
Personally I wouldn't deliberately let it grow. But I wouldn't necessarily go to town on removing it.
Certainly appears to have been sucking in bindweed, brambles and cinquefoil from all corners of the galaxy