No problem! Yes, the toptube is one of the lightest tubes of the frame (and the seatstays cca. 40g for one). But you can't press it with you fingers like some Scott Addict, Wilier Cento, or some similar toptubes of some lighter frames. I could save some more grams on the tubing, but I prefer to make a stiff frame. Probably a Scott Addict toptube would be cca. -20g less, just my guess...
Probably a bit offtopic, but here are some interesting photos from a broken frame that I get last week..probably for most cyclist the "dream frame", but it is quite "scary" to see how is a 2000eur frame made:
Seat-tube (really very thin!)
I already have two friends who cracked the frame by the front dereilleur, wonder why
I can say that my frame will be much cleaner in the inside
..anyway, probably it is interesting for you to see the inside of some frames..