I do not use Transmission because it sucks. LOL The only people who like it are either unix users who use it on a seedbox (who generate so much upload they do not notice the problems), people on Mac's who are clueless, or people who have a personal ax to grind against other Mac torrent clients.
It has a well documented history of over reporting download amounts for at least 7 or 8 years. Find any independent tests which test torrent clients ability to report stats back to the tracker . . . Transmission is always
at or near the bottom. Seriously it has been that way for years
If you are hearing differently you are not listening to someone who knows what they are talking about. I used to staff the oldest Mac only torrent site on the web. There was exactly one staffer there in the roughly 6 years since I joined the site who did not use Vuze/Azureus on their Mac. That one person only used it rarely because he was mainly a seedbox user (where he used rTorrent/ruTorrent). So 95% + of his torrent was done on a client other than Transmission.
Transmission has a lot of folks who love it . . . especially in the Mac community. We wanted to ban the client but there would have been an uproar. So instead we made it a "use at your own risk" client. In other words when (not if but when) Transmission screwed up your stats . . . staff would not fix the stats that Transmission ruined. It happened probably once a week on average where a user would complain about that issue. I can not tell you how many times I saw a user who would say "I am using Transmission anyhow it has never caused a problem for me!". Then a few weeks, months, whatever later that same user would come back and ask why his download amount was off. LOL That happened a lot!!! The site owner (before I staffed the site in question but I knew him from some torrent staff only forums/IRC's/"secret areas of regular forums/etc) actually went to the Transmission developers and offered them unfettered access to his site to try to get the problem solved. The Transmission developers declined the offer. Does that sound like a piece of software you want to use???? LOL
Really it has a well documented problem with over reporting download amounts on private torrent sites. Typically it is in the range of 3% to 10% . . . on most controlled tests the numbers are closer to 10%. If you are only listening to users who use public sites . . . which do not track download amount . . . of course you are not going to hear about that problem.
There are a few sites who have staff who had a personal gripe with Vuze who banned Vuze from their site and did recommend Transmission . . . but that had nothing to do with the performance of either client it was all about ego. So for that reason What.cd banned Vuze but really that had nothing to do with torrent client performance. There are people with personal preferences . . . but my personal preference is based on 7 + years of history of reading what users said about Transmission over reporting download amounts and
reading about what independent testers said about it.
And that is only one of its well documented problems. There was one point about 5 years ago (I think it was) when they released something like 5 "stable" versions in a roughly 4 week period (they have since edited their version history to erase that bit of history . . . seriously does that sound like a quality piece of software?).
Use it if you want . . . just do not come crying to me when it starts causing you serious problems.
If your Java is messed up . . . you need to get that fixed LOL That will effect your memory usage big time especially if you leave your web browser open to sites that use Java. I would strongly recommend fixing that rather than switching clients. That is not a problem you want to ignore. I suspect that many/most of your problems with Vuze are actually problems with your Java installation.
If you have a time machine backup of your computer . . . you could do a complete reinstall of your OS . . . and then recover your data from time machine. That would almost certainly fix your java problem. But that is a "Windows-type" of fix LOL . . . there is probably a way to do a complete reinstall of Java without resorting to that drastic of a solution.
After a little bit of investigation here are some instructions as to how to do that:
If you are having issues when moving files from within Vuze I would suspect that your HD is too full or slow or something which is causing problems. Right now my external RAID 1 (4TB usable space) is almost full and time machine really bogs down my computer. The only time I have problems moving files within Vuze are when a backup is running. If I remember to stop my backup . . . the problem goes away. I have similar problems with other programs which are reading/writing data to that external. I am far from an expert on such things . . . but that is my experience which may or may not be similar to your issues.