Thanks for your reply.
I understand your opinion about 7zip and fully respect it. I was just trying to get more support for goodmerged sets, as many sets, especially those with one gazillion files (TOSEC mainly) can fit in something like 1/4 of their original size, not to mention getting rid of those 45000file folders.

btw is torrentzip support in your plans?

about my second request, i have the following problem; i have some tosec dats, and when i try to rebuild or scan i see that merged and split sets buttons are greyed out. as i understand it, the problem lays with the tosec dat, because it does not state a parent-clone relationship. copying from hymness post in pleasuredome

If you really wish it, you could turn your TOSEC dat into a merged one. That is, end with this:

game (
name "Addams Family, The (1992)(Ocean)"
rom ( name "Addams Family, The (1992)(Ocean)(M3).adf" size ... crc ... md5 ...)
rom ( name "Addams Family, The (1992)(Ocean)(M3)[cr FSN].adf size ... crc ... md5 ..." )
...
)
currently, the tosec dat is like this:

game (
name "Battle Isle (1991)(Ubi Soft)(en-de)(Disk 2 of 3)[a2][bootable]"
description "Battle Isle (1991)(Ubi Soft)(en-de)(Disk 2 of 3)[a2][bootable]"
rom ( name "Battle Isle (1991)(Ubi Soft)(en-de)(Disk 2 of 3)[a2][bootable].adf" size 901120 crc d4c248b7 md5 e444e7d640cc67ae238976fc1669a4b4 )
)

game (
name "Battle Isle (1991)(Ubi Soft)(en-de)(Disk 2 of 3)[a3][bootable]"
description "Battle Isle (1991)(Ubi Soft)(en-de)(Disk 2 of 3)[a3][bootable]"
rom ( name "Battle Isle (1991)(Ubi Soft)(en-de)(Disk 2 of 3)[a3][bootable].adf" size 901120 crc 14edde81 md5 5e8937ea23e64d3b52ab57e913252843 )
)

game (
name "Battle Isle (1991)(Ubi Soft)(en-de)(Disk 2 of 3)[a4][bootable]"
description "Battle Isle (1991)(Ubi Soft)(en-de)(Disk 2 of 3)[a4][bootable]"
rom ( name "Battle Isle (1991)(Ubi Soft)(en-de)(Disk 2 of 3)[a4][bootable].adf" size 901120 crc 8885e099 md5 e67bcd8a4ee675a882ec2a6aa6d1a3f6 )
)

am i right, and i have to convert the dat, or is there any other way?