I have always liked the program, it's a powerful tool for photographers.
However, there are 3 issues that stop this good program, from being great.
1: Zero distortion and perspective correction tools: In this day and age, to not even have a basic slider for barrel distortion correction is a gross oversight, and near unacceptable for WA/Scenic shooters, who need it most. Just about every other raw program out there has this, even budget rip off's such as Arcsoft's Photostudio Darkroom have tools for this (and having tried that one, fairly effective ones), the free Raw Therapee can correct barrel distortion. Silkypix has it too, and the list goes on. Someone needs to "wake up and smell the coffee" at Adobe HQ.
2: Speed. LR has got faster, but even on a decent pc, it's far from a speed demon. It's simply not coded well enough to run as fast as it should do. It's ok speed wise for me, but working on high res film scans, can be a bit of a pain at times. Efficient optimisation is required for software to work at it's best. Adobe have never had a reputation for speed on all their software products. This could be improved..
3: Base Level NR processing on RAW: I raised this one before, and it is still here. Simply put, for high ISO work, or pulling shadows, Adobe gives us an inferior IQ compared to rivals. Raw Therapee can apply 0 NR to images, LR cannot do this. Exactly what goes on is known to adobe, but sliders at 0 for luminance do not give 0 NR. The visual effect of this is that other programs can do this, giving a tight grain pattern, where as LR has a mottled effect in areas of noise.
Other issues have been raised too, soft proofing is one, and does anyone really use web or sideshow much??
Not to moan too much, but a bit of effort here, and we will have something near dead on..