Hmm... well here are some BT vs. IRC stuff I've come up with.
Some channels do not have many bots, and do not have stuff (pack lists, etc) that make it easier for you to use bots. But they do have a BT link that is always in the same place. So In terms of
convenience, BT is probably better for some channels, and equal for others. This is why I use BT all the time for some channels' releases, and IRC for others.
For
speed, again it is channel dependant. Some channels do not have much IRC distro at all, so BT would be faster for them. You'd probably have to wait till someone downloads it from BT to serve it to you, or you may have to wait in line for hours. I find it very funny, though, when there are 3000 clients on a torrent when there are so many free send slots on XDCC bots.
Saying the BT protocol is better may be true generally, but not completely. With IROffer (the program that XDCC bots are ran on) everything can be done remotely. So, if you have a lot of bandwidth, but are never around, you can just run an XDCC bot for a channel. Then, distro heads can control your bandwidth while you aren't even on the computer. With BT seeding, you'd either have to be around, or you would have to setup a way to remotely seed the files. It'd probably involve a lot of FXP-ing, whereas you can send files from one bot to another with XDCC easily. Either way, iroffer is better for its remote access features. I know I shouldn't say this, but a lot of groups hack other computers to serve as XDCC bots. It is kind of like a common practice by now, but I don't think hacking for BT seeds is... I don't even know if it's possible.
Most groups do not release with one seeder (the encoder) anymore. It is slow, obviously. They either release the torrent to the fast, distro team first, or use a Bot / FTP / HTTP to get it to the seeders. The time this takes, is usually longer than setting up XDCC for releasing. (For my distro chan, anyway) Bots are usually a lot faster than seeders, so they can download the files faster. Unless you do not have the time to recruit people to run/acquire bots, or "hire" someone to be a distro head, XDCC is probably better here. Groups that do not really care about speed would probably go with the "encode finishes, encoder seeds, released!" releasing method.
In terms of difficulty of
learning to use, IRC is harder, of course. Though I'm quite surprised at how many people have difficulty with BT installation... I figured out how to use BT in like 2 minutes.
But, it is also not as hard as people say it is. Most of the people who say that probably gave up 1 minute after trying, anyway. There are many resources out there, like ronin's IRC guide. I also wrote one myself
here, if you're interested. My IM contact info is on there as well, so I usually get at least one question every day. I've been getting them for a LONG time, though, (my guide's been around for ~1.5 years) so I'm used to them now. Don't be afraid to ask me if you don't understand something. I know the guide isn't completely dummy proof, so questions help me as well as you, because I know which areas I have to make more clear and so on. I'm actually working on a flash import of the guide right now, so it'd have pictures and stuff to make it easier to understand. I originally had it on a .html file ONLY so that people can download it easily on a tdcc on IRC, but since flash is also a one-file thing, I've decided to work on the flash import. (Learning flash at school right now)
Anyway, it is your choice on what you use to download. But I don't want to hear anyone complaining about IRC unless they've actually experienced it to the fullest. Complaining on how a channel does their releasing is just ridiculous. They can do what they want, however way they want it. If you want them to do it another way, you should just suggest it, and specify a valid reason.