You like it is excuse enough It and the 6.8 are nearly identical ballistically to about 350 yards, and the 6.8 has quite a following among deer and hog hunters as well. The Grendel will have slightly better SD numbers for better penetration though.
I am considering it for a light bolt or single shot build when funds are available. I initially thought 300 BLK (even have the dies). My other considerations are a 32-20, 6x45, 357Max. The latter would simply be the result of reaming a chamber for a single shot I already have, getting proper brass, and sturdier bullets. I think it would be great on deer with 200gr WFNGC cast pills if I could get an accurate load together. The other two option would be relegated to things other than deer, but fun all the same.
I'm in a similar situation. I started a thread in the long gun section that has some good info in it. I'm pretty well committed to a 6.5 at this point, just have to decide on a barrel.
I have used the 6.5 TCU in a 14" Contender several years. I use a 120gr Sierra SP at 2200fps and have had no problems on deer. My shots are normally 100-125 yards max. With the extra velocity the Grendel has, you should have no problems.