While it's likely they might reduce the size of their "Survivor" series over time I don't think it makes sense to introduce another model specifically for both needs.
Looking at their product page they have drives that are designed for specific cases- Extreme performance, ruggedization, Security, and Ultra Compact. It probably doesn't make sense to combine the design intents together- too "Kitchen Sink" at that point.
The bulk may very well be how that model get's it's ruggedization.
For reference, Their Ultra Compact "Vega" models are already similar in size to the SanDisk Cruzer Fit. (Am I the only one that thinks that name sounds like a Diaper?....)
I have two 128GB SanDisk Cruzer Fit's and they perform well enough. They are not as fast as A more "full size" PNY Flash drive but they are fast enough that I don't recall having to sit and wait except for very large transfers.
At that size typically they are designed such that the actual circuitry is all "inside" the connector itself. The USB Shell itself and the Case it is plugged into then becomes a heatsink. And they do get hot.