We own both and are happy with both for different reasons.
2 toys first of all is a bonus. Both feel good and smooth, have a variety of balls running along the length of them to add to the fun and one is slimmer than the other so good for anal and vaginal play. Very good quality toy
what you see is what you get with this, no frills, lumps or bumps. Fairly slim and very smooth so good for anal play too. The only thing about this toy which is not apparent from the picture is the weight. I was completely taken aback by how heavy it is and even though we have had this for a couple of weeks it still surprises me everytime we pick it up. this changes the dynamic of the toy completely for us and heightens the pleasure a lot more. It is an exquisite item.
Is a very tough call...
Verdict - I would not like to be without either, but if I was in your situation I would go for the glass. My decision is made purely on pricing as we bought the metal toy for half price 2 weeks ago when it was on sale.
The glass is also in a 3 for £75 deal...