Do or should you lightmap as you go ?
The reason I ask is because I have been and doing stuff then F4..doing more then F4 again...But this is when strange things kick in.. Like select a building and you get a totally different model with the texture of the model you picked ?

Im worried about spending hours on a map then pressing F4 and it all goes pear shaped
Anyone tried anything big yet ?

It's been so unpredictable so far, I wouldn't do it until the end. Not that I'm making anything large, anyway, but it seems the more you do it, the weirder things get! I've noticed it also doesn't like anything that's been scaled in the fpe. I have a lot of models from Arteria and I've had to scale some down by half, or double in size. If I've scaled them down, the lightmapper moves them apart. (some dungeon corridor segments that I had linked together. I'm not sure what it does with ones I've scaled up since I haven't run across them yet in my experiments, but I'm sure it won't be pretty! This is just a guess but it may be ignoring the scaling and placing them where their respective origins would be without scaling, but I really don't know.

I personally am avoiding using it all together until the bugs associated with it all get cleared...

That would be the safest call! I'm not yet making anything serious, so I don't mind if something goes a little crazy, (losing textures, entities, whatever), but I still like seeing what it does. Sometimes it does a damn good job! Hit or miss though, really.

I don't find much issue with the light mapper... I tend to do it as I go... after I'd added static objects... just using basic stock media for the competition level I have been making has been fine...

I've also noticed that when resizing an entity, it retains the same range of collision.
For example, I put a bridge over a wall, almost at the same wall height, the player when he reaches the height of this wall can not continue, so I reduced the height of the wall in hal; result: player still unable to walk, it is as if an invisible wall prevents the passing, I guess the wall retains the same range of collision, I deleted the wall and now the player can walk across the bridge.

3com

I prefer to test as I go, although that desire wanes as and when it starts taking a long time for bakes. Also, find issues with continual baking and testing, or seem to, not certain by any means., but I always seem to find a floaty shadow that floats over the landscape at some point. It's difficult to really say until we have a more functional mapper, as at the moment you are afraid to bake at the start and by the end you may not be able to anyway! So for me I bake as often as I can and check it is still working after adding new entities. Eventually I may well leave it as intended at the end and therefore save many hours of baking as we go.

Of course the preferable way, for me anyway, would be for the baking to quietly go on in the background in the editor as you are designing it. That way a lot of the bake time would end up being almost invisible to the user. Obviously with a way to enable or disable the feature for people not interested in baking for whatever reason. For me a baked scene looks so much better than a real time scene, it is difficult to understand why some are saying real time looks better. It so doesn't.

That must be what I've been experiencing. Oh, well, so it's a bit wonky. It'll get fixed. Eventually! Still loving the new beta though! So much to play with!