I dont know who you are having this debate with but I will chime in on my exsperience with both.No I dont like the silicone in the corners of glass,yes acrylic is clearer but scratches easily.Make sure you use the proper thickness of acrylic or you will have the proplem I had with seperation of seams.Also acrylic tanks should not have metal halide lights as they produce to much heat and light for the seams to stay true.I use both,glass is my display and some sale tanks,acrylic is great for making divided tanks for sale tanks and frag swap tanks the only real drawback for me is the scratching issue.IMO.When it comes down to rubber meeting the road.A fish only tank with minimum surface cleaning I would go with acrylic for showmanship and diversty in style or shape.With a full blown mixed reef tank I would go glass for strength and the ability to clean it.Also as far as someone bumping into it and causing a problem, the properlly built glass tank can take alot of abuse.I have seen a glass tank full of coral and fish (200gal.) plus hit with a hammer and not budge or crack.I have seen a 200gal plus acrylic tank seperate due to lack of proper thickness and the use of metal halide lighting.If you can build it,clean it and be happy with your creation either isx equally good.I think it comes down to personal prefefence.Both are strong,both are beautiful if done correctlly.I dont know if this helps any but it is my .02 worth.LOL
Jason