Edelman doesn't have the regular season resume of a HOF receiver. I think Swan is a decent comp as he got in the HOF mostly because of his postseason numbers but he also is a slightly more accomplished receiver overall.
I think Wes Welker is the Patriots best slot receiver of all time. Probably Brady's all time favorite receiver. His regular season resume is close to HOF worthy. He'd probably get in if he had won a Super Bowl. Letting Welker sign with Denver is an underrated mistake on Belichick's part. Welker was the final peice of Manning's historic 2013 season to go along with Thomas (WR), Decker and Thomas (TE).
Amendola did not work out in NE as expected but that gets glossed over because he was such a vital contributor in the postseasons. The emergence of Edelman turned out to be the replacement of Welker but even still you nearly had to combine the production of Edelman and Amendola to equal what Welker had brought to the offense.
Unfortunately I think Welker is remembered more for his drop in Super Bowl 46 than anything else.
Patriots all-time best wide receivers:
1. Stanley Morgan
2. Wes Welker
3. Julian Edelman
4. Randy Moss
5. Troy Brown