Adobe reads threads here, and some known bugs in this area have been mentioned here.

There's not much to talk about on this issue.  There are performance problems with the beta.  We know that, and they know that.  They have to fix the performance bugs (such as the one that causes massive slowdowns on upgraded images) and optimize as best they can.  Period.

Look, I could give a rat's tail end about maps and photo books in this application. It's all fluff that makes me fearful of what kind of stress it's putting on the whole of the engine. But Adobe isn't making the app for just me and the Lightroom team isn't new to this game. This is their 4th major public beta go around and they have had to deal with this every time (especially with the performance issue before it's baked). the performance issue is something that the team knows about, know's that they can't release a final with these problems without all hell coming down on them from every pro (and other) that has to depend on the program managing their lively hood. We all want it to be perfect out of the box... the thing is it hasn't been put in the box yet. The more time they spend managing our issues with a program that we shouldn't be using except for a geeky fun time play toy, the less time they have to actually get the work done. It's perfectly reasonable that they are going to talk about the features that they are still making the recipe for (whether I want those features or not).

So when is the second beta coming out?

Simon,

the sluggishness is a problem with LR since version 1 and IMO has very little to do with the beta stadium of LR4. If the sluggishness would be really be adressed, than LR4 would have to be a lot faster than all previous LR versions,.....what I seriously doubt.

Lr4 seems pretty good (for a beta) and most of the performance is comparable to Lr3 (which I find totally acceptable on my system: Core i7-2600 3.4ghz, 16Gb RAM, SSD system disk, 2x1Tb HDD in mirrored RAID array, Radeon HD6850 1Gb). The only sluggish thing is switching modules, e.g. "slideshow" to "print" is very slow.

So far I could'nt  find any difference to LR3, means same performance. Tried the stamp, brush etc. where others reported bad performance.

Working on an Core I7 Q 720 @ 1,6GHZ, Win 7 64bit, 6 GB RAM.

Oli