Advice on the negative points on SLA powered lamps

Over here in the UK we have a couple of companies which sell SLA rechargeable hand lamps which have good performance and long discharge times. I am aware however that one two CPF members have commented that they wouldn't touch SLA powered lamps, Why?
Any comments appreciated!

Doug

I think the main point with SLA batteries is they`re big and heavy, not giving as much capacity (= run time) compared to an equivalent size or weight of NiMH or NiCd. Also they don`t like to be fully discharged for any length of time. Leave one flat overnight if you can`t get to the charger and chances are, it`s dead for good

Me- I kind of like them, mainly since we use them in work and there`s always half-dead or otherwise good "suspect" ones lying around headed for the trash, that I can scavenge. Mostly just for project stuff, I don`t have any of those whopping great 3-million candlepower lanterns yet, but it`s only a matter of time....