It all boils down to what you "need/prefer".
I don't need a tenkeypad attatched to my board but prefer it! But then again, I grew up with them and never heard of tenkeyless in my youth. It appears that tenkeyless is the movement of today but then again, it depends on your needs too. I don't game but like programming/surfing the net/email, etc. I have more opportunity for using the tenkeypad and therefore want it.
Do you think you'll see tenkeyless boards at workplaces? Most people do a little number crunching at home/work and it is just nice to have the tenkeypad right there. And it's cost effective to get it attatched vs an extra keypad. But what ever. It's your decision only and it has to make you happy in the end.
If you're truly unsure, then you could do what was suggested ang buy the tenkeyless first and see what you think and if not likely, then get some of your money back and get the 104.
Costs more that way but it is a paid for decision then that's a true one. I did that with my boards and intend for a huge sale at some point, as I've decided on my choice.
How I would have loved to see a RF and Cherry store to "try" before buy option.
Oh, on the uniform weight vs variable thing? I would prefer the 55g weight personally but I "need" lighter weight, due to some RSI troubles. I would love a uniform "45g" weight board but already have a variable weight 103 RF9white) and will be happy with that, since I paid for that first.
Again, need vs want.