Look for this Mondays post by 'The Aether' - under the words 'clear enough?, I hope so, click on the 'See More' for the install instructions and the posted zip file for MC152.
The rather huge log file that was being created client-side on the MC151 version is not happening any more (at least for me, and hopefully for you). Entering the Aether you will still find the world a little 'sticky', you'll understand if you play, but on the whole, I found it quite playable now. I'd given up on the MC151 version because of the lag created by the constant errors and the ever growing log file.
For those having issues with the blocks not advertised in the Aether config file, I've found :
Aether:Green Skyroot Sapling. ID: 179
Aether:Golden Oak Sapling. ID: 180
Aether:Blue Skyroot Leaves. ID: 218
Aether:Dark Blue Skyroot Leaves. ID: 221
Aether:Blue Skyroot Sapling. ID: 222
Aether:Purple Crystal Leaves. ID: 225
Aether:Purple Crystal Sapling. ID: 226
Aether:Dark Blue Skyroot Sapling. ID: 230
I may have missed some others, but I don't think so, all the rest that the Aether uses are in the config file. Granted I had conflicts with IC2, as someone else has posted about, but IC2's ID's can be moved. If you have already started a world, then you will also have to edit the file : "ic2_map.cfg"
This can be found server-side in your 'world' directory. Change it to match your client-side config, not forgetting to change the server/config/IC2.cfg file as well. When I checked, I hadn't got any of the block ID's for IC2 that I needed to change as real blocks in my current world. I have no idea what would happen if you already have some of these blocks in existance in your world. So back up your world first and "WARNING, CHANGE AT YOUR OWN RISK"
For those worried about Zeyphers, look in the lower part of the Aether's config file - you can change the amount being generated, along with many of the other Aether wild-life to, so you can make it safer, or much more dangerous depending on your taste..
For those wondering, I've tried the MC152 version with up to 80 mods installed, and still everything works ok (or it has up to now, I haven't tried all combinations with everything yet, and probably never will), but I've had 2 hours of play without a crash.
Last thing, for those who build the portal and throw a bucket of water in, Yes, I end up with flowing water coming out of the portal to - all you have to do is remove the water and try again. Its sometimes taken me 6 - 8 tries, but eventually the portal will work, and hopefully it will for you to. Great job by the people working on it, and many thanks, I've always wanted to play this in SMP.
So, in fact, you already have the file, you just need to extract it from the downloaded MC152 zip and put it in the right place.