studio is one of the best choice to go. i bought it 1 year back and still running like a charm (no format, no nothing fancy)
yes.. a bit slow compare to new.. more load to boot up and it's normal ( i installed more and more software on it).
good for gaming (i am also not a hardcore gamer), so i play it once a while when i got time.
my batt life is good coz i'm using 9 cell that can easily last for 4 hours.
as mentioned 9 cell can go for 4 hours, slot load is standard for studio.
no way to change i believe.
my dvd rom serve me well.. no any issue like urs le... maybe different batch different dvd model.

My studio's warranty just expired!~ Still going strong... Battery 100% charged can still manage to go up to 3 hours!!(pure surfing only... Not PSing or Gaming)... My DVD also not giving me prob(btw... i rarely use it too...) The speaker is nice(but i just got an edifier m1335 to get better sound). Still no scratch on my s1555(protected with transparent sticker from ezstick(not confirm... forgot edi)
The only prob for me is... the volume of the headphone jack... with headphone... around 36 is max i will go... for my new 2.1 speakers, i will go until about 20 only... 100 will kill them(headphone and speakers) i guess...

so better extend ur warranty when u purchasing the laptop..XD

Hahahaha Just played with sound test. My S15 speaker can play range from 80Hz to around 17kHz. My audible range la... hahahah

even default clock speed will fry already
subwoofer is available for all types of studio 15