Update:
Having messed about for a few weeks now I can say the following - this is purely for information in case someone is curious, and also as I hope I might be corrected and find a way to improve my working
* I agree on some of the cool tools in lightroom such as the per color adjustment - although lightroom is way below lightzone on that front where you can limit any effect to a color (or range) automagically. I am really tempted to buy lightzone just for that - actually would have bought it when it was on promotion last week except i lost my job so no $150+ software purchases (that and LZ seem to have messed up the exif date data on exported images, weird)
* I like the on-image tweaks available in lightroom. Some are available in acdsee but only in the destructive mode editor - although that editor is a lot more powerful
* i like the built-in versioning in lightroom, although i still tend to export different versions instead
* there *is* partial undo in acdsee RAW - its the little arrow next to the reset button. By default undo only undoes the work on the tab you are on, not everything, but you can undo everything or what has been done on other tabs.
* theres also before/after comparison although not as smooth as in LR
* other tools I get better results in acdsee which are partly familiarity - I also often use the channel combination options in the "non raw" editor (i.e. apply an effect to a new layer and merge back with the original using any of the common channel modes and custom transparency. Alas it only can do one set at once so is limited in flexibility (no tweaking the sharpness of bright and dark separately without a lot of trial and error, whereas a tool with full layers support can do it). The Shadows/Highlight tool in acdsee is very nice and almost as good as lightzone's zone tool.
* lightroom has a good workflow, although it seems aimed at printing not exporting/uploading. I work mostly digital only, no printing, and exporting seems a long winded process even after you save standard settings.
* acdsee workflow is less flexible - i like to go through the images as RAW fixing the basics then export all at once, and I didnt see an option for that
* lightroom seems far less able to cope with moving images - i move images every couple days to my external drive and this seems to puzzle lightroom
* lightroom's local effects can be very handy although most of the time i forget to even think about them
* i find acdsee much easier to use for image management and tagging though - could just be habit (I havent found a way to make lightroom detect that files have moved yet, i.e. theres no cleanup mode)
* i dont have the quality issues in acdsee that you have - most likely because it is a different camera and format, so the default settings are different. I noticed that lightroom does apply some automated fixes based on my camera model, which acdsee does not - so they look possibly a bit better on opening. But once I do the same kind of work, I have equivalent images - often the levels are a bit more subtle in acdsee but it is mostly because i am more adept at using their shadow/highlights tool. Color is often better out of lightroom, but that is because the per color HSL tool allows for more tweaking (whereas i have to go to a separate program to do this in acdsee)
* in both those tools I miss the flexibility that photoshop offers, as even with my limited knowledge i know how to do stuff in photoshop that i havent found how to do in other tools - such as different color casts for shadows/highlights, more clever sharpening (although lightzone had a way to achieve some of this, and in acdsee normal edit the channel mix allows some).
Of course you can pick up acdsee pro for around $100 whereas lightroom costs a lot more. Its almost ridiculous in pounds.
I am not saying acdsee is great, except perhaps for management, but i bought the power pack v6 cheap, then got good offers for upgrades so it was a very reasonable option for me. And I can get very good results with the (destructive) editor, in very little time.
I wish I could justify the price of photoshop&lightroom -especially since i spend an awful lot of time trying to figure out how to get certain things done in other software - but I really cannot, you're talking £1000 altogether! - so I will continue to fumble trying to find a tool that makes it easier to a)get the full range of a picture optimally b)allow for the right kind of control of good sharpening (for everything else I think i can make do with PSP and photoimpact)
PS: still doing blipfoto and taken more pictures than is reasonable so I am now struggling to process-and-tag these!