I chose titanium because it is tough, temp stable, doesnt rust, it has a much harder surface than aluminium so unlikely to be damaged when my scraper is used.
so I thought I would probably only need to buy 2 plates for the life of the printer where as with the glass plates its a continuous problem, the cost was around £90.00 per plate. the plates were laser cut so i had to smooth the sides and corners before use.
Titanium is a lot lighter than steel and I was trying to not add too much weight to the bed as the springs under it are not that strong especially at the back where half of the weight of the plate is held up by a single spring on the end, the plates weighed 800g compared to 560g for the original plate, I could have tried a 2mm thickness which would have been around 530g and reworked the clips but i wanted the option of using the glass for some materials.
the other advantage is that when you remove a plate from the printer it would be impossible to break it through dropping or accidental rough handling or temperature shock.
Being metal the heat from the heated bed is conducted more efficiently to the surface.
Considering the £3000 price tag for the printer I am less concerned about the £180 to improve the usability of it.