So, I'm sure it's just me, but the last 24 hours have pretty much doomed my playthrough. I really don't understand it. I've never seen these kinds of numbers in other packs with some/not all of these same mods. I'll try to be succinct.
I was using opaque itemducts, and when I could upgraded to opaque impulse itemducts for everything. cobblegen to pulverizers (multiple) to create gravel/sand/dust. huge set of AA's (5 sets) +1 AA set for hammering. SFM controls all of that with enderstorage. 3 smelteries using itemducts to process goods.
Now, all was OK. I had about 40-50 FPS (down from about 60 when I started) and I decided to build from the bottom of my large towers back a bit and then up to make some large areas for RC tanks (since no extra cells). I had built 2 RC tanks and when I had gone up elevators I started noticing a TON of lag from when I hit space to it moving me up. going up 18 flights this way was very very bad. I ended up getting block placing lag and everything was stopped in production. I decided to add opis so I can see what happened. quit mc, added opis, reloaded. Things were still laggy so ran opis. I had 35k us (pico? seconds) handler in the TE grid handler. googled, found alot of pissed people but no real ways to relieve the issue. Concensus was that it's item stuffing. I don't make a habit of using overload chests cause I purposely edit the source duct to 1 or 4 stack size depending on what I'm doing. After trying to do everything I could possibly do, I went around and very slowly started removing all my ducts. took me about an hour or more. No change. Fluiducts next. No change. Exit mc, reload. no change. Ok. all that was left was just some onesie twosie ducts that can't stuff so I couldn't understand. reboot machine. reload mc? Down to about 3k pico secs. reboot? Really? I updated java a while back for a pack to latest java 7 that required R55(iirc). Maybe that's issue, dunno. Either way, I destroyed all my work for ... who knows. should have rebooted at the beginning but I've never had that issue with MC. I have 32gb of memory on this machine. quitting mc and restarting always has fixed any issues before.
The thing I don't get is why it started getting laggy, etc.. while I was building with blocks and nothing with ducts or anything else. When I broke the ducts, I got maybe 2-3 stacks of various things altogether. doesn't make sense from stuffing perspective.
Anyways, right now, I'm pretty disheartened to continue on. I may start over again after jampacked or some time around there.
Suggestion: I would definately add opis (even if just set to disabled) so people can add it easily to troubleshoot issues. You don't include a minimap so maybe just add it outright.
Also, I found a glitch with ender tanks and infinite liquids which boggles my mind since I don't get a chance to use them much since they aren't in packs always. Thus, that sorta ruined me for my mob trap with grinder since I went downstairs and had a RC tank full of essence (10mil? - iron). jeez.
I still think this pack is awesome and I don't fully fault it for the issues since I seem to be the only one having them. The dimensional thing tho could be causing these probs but no clue why or how. As a side note, with my extensive base in one agskies playthrough, I had something like 100 crucibles w/lava and a huge base of stuff. lots of production. 6 smelteries. I ran opis then cause I had some FPS (not tps) lag and found the handler on top but sitting around 9k or so. This in comparison was about 1/4 the size if not much smaller, so again, doesn't make any sense. In a post, jaded stated their usual method for evaluating things is removing railcraft (no explanation given). See first page at bottom:
http://forum.feed-the-beast.com/threads/thermal-expansion-70-000-u-s-cause-tps-drop-help.44675/